fix: include quantity in getAllItems select, createItem values, and updateItem type

Quantity was missing from three places in item.service.ts:
- getAllItems didn't select it (API returned undefined)
- createItem didn't pass it to insert (always used DB default of 1)
- updateItem type didn't include it (silently stripped from updates)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -2,9 +2,7 @@ name: CI
 
 on:
   push:
-    branches: [Develop]
   pull_request:
-    branches: [Develop]
 
 jobs:
   ci:
@@ -26,3 +24,33 @@ jobs:
 
       - name: Build
         run: bun run build
+
+  e2e:
+    needs: ci
+    runs-on: docker
+    container:
+      image: mcr.microsoft.com/playwright:v1.59.1-noble
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install Bun
+        run: |
+          apt-get update && apt-get install -y unzip
+          curl -fsSL https://bun.sh/install | bash
+          echo "$HOME/.bun/bin" >> $GITHUB_PATH
+
+      - name: Install dependencies
+        run: |
+          export PATH="$HOME/.bun/bin:$PATH"
+          bun install --frozen-lockfile --ignore-scripts
+
+      - name: Build client
+        run: |
+          export PATH="$HOME/.bun/bin:$PATH"
+          bun run build
+
+      - name: Run E2E tests
+        run: |
+          export PATH="$HOME/.bun/bin:$PATH"
+          CI=true bun run test:e2e

.gitignore

@@ -226,6 +226,11 @@ uploads/*
 # Worktrees
 .worktrees/
 
+# Playwright
+e2e/test.db
+test-results/
+playwright-report/
+
 # Claude Code
 .claude/
 

.planning/PROJECT.md

@@ -80,13 +80,13 @@ Replaces spreadsheet-based gear tracking workflow.
 - **Runtime**: Bun — used as package manager and runtime
 - **Design**: Light, airy, minimalist — white/light backgrounds, lots of whitespace, no visual clutter
 - **Navigation**: Dashboard-based home page, not sidebar or top-nav tabs
-- **Scope**: No auth, single user for v1
+- **Scope**: Single user with cookie/API key auth
 
 ## Key Decisions
 
 | Decision | Rationale | Outcome |
 |----------|-----------|---------|
-| No auth for v1 | Single user, simplicity first | ✓ Good |
+| Cookie/API key auth | Single user, public read + authenticated write | ✓ Good |
 | Generic data model | Support any hobby, not just bikepacking | ✓ Good |
 | Dashboard navigation | Clean entry point, not persistent nav | ✓ Good |
 | Bun runtime | User preference | ✓ Good |

CLAUDE.md

@@ -19,8 +19,10 @@ bun run db:generate         # Generate Drizzle migration from schema changes
 bun run db:push             # Apply migrations to gearbox.db
 
 # Testing
-bun test                    # Run all tests
+bun test                    # Run all unit/integration tests
 bun test tests/services/item.service.test.ts  # Run single test file
+bun run test:e2e            # Run Playwright E2E tests
+bun run test:e2e:ui         # Playwright UI mode for debugging
 
 # Lint & Format
 bun run lint                # Biome check (tabs, double quotes, organized imports)
@@ -55,9 +57,16 @@ bun run build               # Vite build → dist/client/
 - **Timestamps**: stored as integers (unix epoch) with `{ mode: "timestamp" }`.
 - Tables: `categories`, `items`, `threads`, `threadCandidates`, `setups`, `setupItems`, `settings`, `users`, `sessions`, `apiKeys`.
 
-### Testing (`tests/`)
-- Bun test runner. Tests at service level and route level.
-- `tests/helpers/db.ts`: `createTestDb()` creates in-memory SQLite with full schema and seeds an "Uncategorized" category. When adding schema columns, update both `src/db/schema.ts` and the test helper's CREATE TABLE statements.
+### Testing (`tests/` and `e2e/`)
+- **Unit/integration**: Bun test runner (`bun test`). Tests at service level and route level.
+- `tests/helpers/db.ts`: `createTestDb()` creates in-memory SQLite via Drizzle migrations and seeds an "Uncategorized" category.
+- **E2E**: Playwright (`bun run test:e2e`). Tests in `e2e/` run against a seeded SQLite database with the server in production mode. Seed script: `e2e/seed.ts`.
+
+## Branching
+
+- **Develop** is the main branch. Keep it clean — don't commit large feature work directly.
+- For each new brainstorming/implementation session, create a feature branch off Develop (e.g., `feature/setup-impact-preview`, `fix/error-handling`).
+- Merge back to Develop via PR or fast-forward merge when the work is complete and verified.
 
 ## Path Alias
 

bun.lock

@@ -24,6 +24,7 @@
       },
       "devDependencies": {
         "@biomejs/biome": "^2.4.7",
+        "@playwright/test": "^1.59.1",
         "@tanstack/react-query-devtools": "^5.91.3",
         "@tanstack/react-router-devtools": "^1.166.7",
         "@tanstack/router-plugin": "^1.166.9",
@@ -185,6 +186,8 @@
 
     "@oxc-project/types": ["@oxc-project/types@0.115.0", "", {}, "sha512-4n91DKnebUS4yjUHl2g3/b2T+IUdCfmoZGhmwsovZCDaJSs+QkVAM+0AqqTxHSsHfeiMuueT75cZaZcT/m0pSw=="],
 
+    "@playwright/test": ["@playwright/test@1.59.1", "", { "dependencies": { "playwright": "1.59.1" }, "bin": { "playwright": "cli.js" } }, "sha512-PG6q63nQg5c9rIi4/Z5lR5IVF7yU5MqmKaPOe0HSc0O2cX1fPi96sUQu5j7eo4gKCkB2AnNGoWt7y4/Xx3Kcqg=="],
+
     "@reduxjs/toolkit": ["@reduxjs/toolkit@2.11.2", "", { "dependencies": { "@standard-schema/spec": "^1.0.0", "@standard-schema/utils": "^0.3.0", "immer": "^11.0.0", "redux": "^5.0.1", "redux-thunk": "^3.1.0", "reselect": "^5.1.0" }, "peerDependencies": { "react": "^16.9.0 || ^17.0.0 || ^18 || ^19", "react-redux": "^7.2.1 || ^8.1.3 || ^9.0.0" }, "optionalPeers": ["react", "react-redux"] }, "sha512-Kd6kAHTA6/nUpp8mySPqj3en3dm0tdMIgbttnQ1xFMVpufoj+ADi8pXLBsd4xzTRHQa7t/Jv8W5UnCuW4kuWMQ=="],
 
     "@rolldown/binding-android-arm64": ["@rolldown/binding-android-arm64@1.0.0-rc.9", "", { "os": "android", "cpu": "arm64" }, "sha512-lcJL0bN5hpgJfSIz/8PIf02irmyL43P+j1pTCfbD1DbLkmGRuFIA4DD3B3ZOvGqG0XiVvRznbKtN0COQVaKUTg=="],
@@ -675,6 +678,10 @@
 
     "pkce-challenge": ["pkce-challenge@5.0.1", "", {}, "sha512-wQ0b/W4Fr01qtpHlqSqspcj3EhBvimsdh0KlHhH8HRZnMsEa0ea2fTULOXOS9ccQr3om+GcGRk4e+isrZWV8qQ=="],
 
+    "playwright": ["playwright@1.59.1", "", { "dependencies": { "playwright-core": "1.59.1" }, "optionalDependencies": { "fsevents": "2.3.2" }, "bin": { "playwright": "cli.js" } }, "sha512-C8oWjPR3F81yljW9o5OxcWzfh6avkVwDD2VYdwIGqTkl+OGFISgypqzfu7dOe4QNLL2aqcWBmI3PMtLIK233lw=="],
+
+    "playwright-core": ["playwright-core@1.59.1", "", { "bin": { "playwright-core": "cli.js" } }, "sha512-HBV/RJg81z5BiiZ9yPzIiClYV/QMsDCKUyogwH9p3MCP6IYjUFu/MActgYAvK0oWyV9NlwM3GLBjADyWgydVyg=="],
+
     "postcss": ["postcss@8.5.8", "", { "dependencies": { "nanoid": "^3.3.11", "picocolors": "^1.1.1", "source-map-js": "^1.2.1" } }, "sha512-OW/rX8O/jXnm82Ey1k44pObPtdblfiuWnrd8X7GJ7emImCOstunGbXUpp7HdBrFQX6rJzn3sPT397Wp5aCwCHg=="],
 
     "prebuild-install": ["prebuild-install@7.1.3", "", { "dependencies": { "detect-libc": "^2.0.0", "expand-template": "^2.0.3", "github-from-package": "0.0.0", "minimist": "^1.2.3", "mkdirp-classic": "^0.5.3", "napi-build-utils": "^2.0.0", "node-abi": "^3.3.0", "pump": "^3.0.0", "rc": "^1.2.7", "simple-get": "^4.0.0", "tar-fs": "^2.0.0", "tunnel-agent": "^0.6.0" }, "bin": { "prebuild-install": "bin.js" } }, "sha512-8Mf2cbV7x1cXPUILADGI3wuhfqWvtiLA1iclTDbFRZkgRQS0NqsPZphna9V+HyTEadheuPmjaJMsbzKQFOzLug=="],
@@ -879,6 +886,8 @@
 
     "node-abi/semver": ["semver@7.7.4", "", { "bin": { "semver": "bin/semver.js" } }, "sha512-vFKC2IEtQnVhpT78h1Yp8wzwrf8CM+MzKMHGJZfBtzhZNycRFnXsHk6E5TxIkkMsgNS7mdX3AGB7x2QM2di4lA=="],
 
+    "playwright/fsevents": ["fsevents@2.3.2", "", { "os": "darwin" }, "sha512-xiqMQR4xAeHTuB9uWm+fFRcIOgKBMiOBP+eXiyT7jsgVCq1bkVygt00oASowB7EdtpOHaaPgKt812P9ab+DDKA=="],
+
     "readdirp/picomatch": ["picomatch@2.3.1", "", {}, "sha512-JU3teHTNjmE2VCGFzuY8EXzCDVwEqB2a8fsIvwaStHhAWJEeVd1o1QD80CU6+ZdEXXSLbSsuLwJjkCBWqRQUVA=="],
 
     "recast/source-map": ["source-map@0.6.1", "", {}, "sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g=="],

bunfig.toml

@@ -0,0 +1,2 @@
+[test]
+root = "tests/"

docs/superpowers/plans/2026-04-03-codebase-improvements.md

@@ -0,0 +1,661 @@
+# Codebase Improvements Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Harden the server (explicit DB context, param validation, error handling, rate limiting), add client error boundaries, split the oversized collection route into focused components, and fix stale docs.
+
+**Architecture:** Server changes are middleware-level (DB context, error handler, rate limiter) plus a small utility for param parsing. Client changes are a TanStack Router error boundary on the root route and extracting three tab components from the 634-line collection route. Docs change is a one-line fix in PROJECT.md.
+
+**Tech Stack:** Hono middleware, TanStack Router errorComponent, React, TypeScript
+
+---
+
+### Task 1: Explicit DB Context Middleware
+
+**Files:**
+- Modify: `src/server/index.ts:1-59`
+- Modify: `src/server/routes/settings.ts:3,12` (remove prodDb fallback)
+
+- [ ] **Step 1: Add DB import and middleware to server index**
+
+In `src/server/index.ts`, add the import for the production database at the top, alongside existing imports:
+
+```ts
+import { db as prodDb } from "../db/index.ts";
+```
+
+Then add a middleware **before** the auth middleware (before line 26) that sets the DB on every API request:
+
+```ts
+// Inject production database into request context
+app.use("/api/*", async (c, next) => {
+	c.set("db", prodDb);
+	return next();
+});
+```
+
+- [ ] **Step 2: Fix auth middleware comment**
+
+In the same file, update the comment on the auth middleware from:
+
+```ts
+// Auth middleware for write operations (POST/PUT/DELETE) on non-auth routes
+```
+
+to:
+
+```ts
+// Auth middleware for write operations (POST/PUT/PATCH/DELETE) on non-auth routes
+```
+
+- [ ] **Step 3: Remove prodDb fallback from settings route**
+
+In `src/server/routes/settings.ts`, remove the `prodDb` import and fallback. Change:
+
+```ts
+import { db as prodDb } from "../../db/index.ts";
+```
+
+Remove this import entirely.
+
+Change both occurrences of:
+```ts
+const database = c.get("db") ?? prodDb;
+```
+to:
+```ts
+const database = c.get("db");
+```
+
+- [ ] **Step 4: Run tests**
+
+Run: `bun test`
+Expected: All 183 tests pass. Tests already set `c.set("db", testDb)` so this change doesn't affect them.
+
+- [ ] **Step 5: Run lint**
+
+Run: `bun run lint`
+Expected: No errors.
+
+- [ ] **Step 6: Commit**
+
+```bash
+git add src/server/index.ts src/server/routes/settings.ts
+git commit -m "fix: add explicit DB context middleware for all API routes"
+```
+
+---
+
+### Task 2: Route Parameter Validation
+
+**Files:**
+- Create: `src/server/lib/params.ts`
+- Modify: `src/server/routes/items.ts`
+- Modify: `src/server/routes/categories.ts`
+- Modify: `src/server/routes/threads.ts`
+- Modify: `src/server/routes/setups.ts`
+- Modify: `src/server/routes/auth.ts:187-189`
+
+- [ ] **Step 1: Create parseId helper**
+
+Create `src/server/lib/params.ts`:
+
+```ts
+/**
+ * Parse a route parameter as a positive integer ID.
+ * Returns the number if valid, or null if the string is not a positive integer.
+ */
+export function parseId(raw: string): number | null {
+	const id = Number(raw);
+	if (!Number.isInteger(id) || id <= 0) return null;
+	return id;
+}
+```
+
+- [ ] **Step 2: Update items routes**
+
+In `src/server/routes/items.ts`, add the import:
+
+```ts
+import { parseId } from "../lib/params.ts";
+```
+
+Replace all `Number(c.req.param("id"))` patterns. For each route that uses an ID param, add validation. Example for `GET /:id`:
+
+```ts
+app.get("/:id", (c) => {
+	const db = c.get("db");
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid item ID" }, 400);
+	const item = getItemById(db, id);
+	if (!item) return c.json({ error: "Item not found" }, 404);
+	return c.json(item);
+});
+```
+
+Apply the same pattern to `PUT /:id` and `DELETE /:id`. In each case, add `const id = parseId(...)` + the null check returning 400 right after.
+
+- [ ] **Step 3: Update categories routes**
+
+In `src/server/routes/categories.ts`, add the import:
+
+```ts
+import { parseId } from "../lib/params.ts";
+```
+
+Replace `Number(c.req.param("id"))` with `parseId(c.req.param("id"))` in `PUT /:id` and `DELETE /:id`, adding the null check:
+
+```ts
+const id = parseId(c.req.param("id"));
+if (!id) return c.json({ error: "Invalid category ID" }, 400);
+```
+
+- [ ] **Step 4: Update threads routes**
+
+In `src/server/routes/threads.ts`, add the import:
+
+```ts
+import { parseId } from "../lib/params.ts";
+```
+
+Replace all `Number(c.req.param(...))` calls. There are 8 occurrences across these handlers:
+- `GET /:id` — `const id = parseId(c.req.param("id"))`
+- `PUT /:id` — same
+- `DELETE /:id` — same
+- `POST /:id/candidates` — `const threadId = parseId(c.req.param("id"))`
+- `PUT /:threadId/candidates/:candidateId` — `const candidateId = parseId(c.req.param("candidateId"))`
+- `DELETE /:threadId/candidates/:candidateId` — same
+- `PATCH /:id/candidates/reorder` — `const threadId = parseId(c.req.param("id"))`
+- `POST /:id/resolve` — `const threadId = parseId(c.req.param("id"))`
+
+For each, add the null check returning 400 with a descriptive message like `"Invalid thread ID"` or `"Invalid candidate ID"`.
+
+- [ ] **Step 5: Update setups routes**
+
+In `src/server/routes/setups.ts`, add the import:
+
+```ts
+import { parseId } from "../lib/params.ts";
+```
+
+Replace all `Number(c.req.param(...))` calls. There are 6 occurrences:
+- `GET /:id` — `const id = parseId(c.req.param("id"))`
+- `PUT /:id` — same
+- `DELETE /:id` — same
+- `PUT /:id/items` — same
+- `PATCH /:id/items/:itemId/classification` — both `setupId` and `itemId`
+- `DELETE /:id/items/:itemId` — both `setupId` and `itemId`
+
+For the classification and item removal routes with two params:
+
+```ts
+const setupId = parseId(c.req.param("id"));
+const itemId = parseId(c.req.param("itemId"));
+if (!setupId || !itemId) return c.json({ error: "Invalid ID" }, 400);
+```
+
+- [ ] **Step 6: Update auth routes**
+
+In `src/server/routes/auth.ts`, add the import:
+
+```ts
+import { parseId } from "../lib/params.ts";
+```
+
+Update `DELETE /keys/:id` (line 187-189):
+
+```ts
+app.delete("/keys/:id", requireAuth, (c) => {
+	const db = c.get("db");
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid key ID" }, 400);
+	deleteApiKey(db, id);
+	return c.json({ ok: true });
+});
+```
+
+- [ ] **Step 7: Run tests**
+
+Run: `bun test`
+Expected: All 183 tests pass. Existing tests use valid integer IDs so no breakage.
+
+- [ ] **Step 8: Run lint**
+
+Run: `bun run lint`
+Expected: No errors.
+
+- [ ] **Step 9: Commit**
+
+```bash
+git add src/server/lib/params.ts src/server/routes/items.ts src/server/routes/categories.ts src/server/routes/threads.ts src/server/routes/setups.ts src/server/routes/auth.ts
+git commit -m "fix: validate route ID parameters, return 400 for invalid IDs"
+```
+
+---
+
+### Task 3: Centralized Error Handler
+
+**Files:**
+- Modify: `src/server/index.ts`
+
+- [ ] **Step 1: Add onError handler**
+
+In `src/server/index.ts`, add the error handler after the app is created (after `const app = new Hono()`) but before any routes:
+
+```ts
+// Centralized error handler
+app.onError((err, c) => {
+	console.error(`[${c.req.method}] ${c.req.path}:`, err);
+	const message =
+		process.env.NODE_ENV === "production"
+			? "Internal server error"
+			: err.message || "Internal server error";
+	return c.json({ error: message }, 500);
+});
+```
+
+- [ ] **Step 2: Run tests**
+
+Run: `bun test`
+Expected: All 183 tests pass.
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add src/server/index.ts
+git commit -m "fix: add centralized error handler for unhandled exceptions"
+```
+
+---
+
+### Task 4: Rate Limiting on Auth Endpoints
+
+**Files:**
+- Create: `src/server/middleware/rateLimit.ts`
+- Modify: `src/server/routes/auth.ts`
+
+- [ ] **Step 1: Create rate limiter middleware**
+
+Create `src/server/middleware/rateLimit.ts`:
+
+```ts
+import type { Context, Next } from "hono";
+
+interface RateLimitEntry {
+	count: number;
+	resetAt: number;
+}
+
+const store = new Map<string, RateLimitEntry>();
+
+const MAX_ATTEMPTS = 5;
+const WINDOW_MS = 15 * 60 * 1000; // 15 minutes
+
+function getClientIp(c: Context): string {
+	return c.req.header("x-forwarded-for")?.split(",")[0]?.trim() || "unknown";
+}
+
+function cleanup() {
+	const now = Date.now();
+	for (const [key, entry] of store) {
+		if (now >= entry.resetAt) {
+			store.delete(key);
+		}
+	}
+}
+
+export async function rateLimit(c: Context, next: Next) {
+	cleanup();
+
+	const ip = getClientIp(c);
+	const key = `${ip}:${c.req.path}`;
+	const now = Date.now();
+
+	const entry = store.get(key);
+
+	if (!entry || now >= entry.resetAt) {
+		store.set(key, { count: 1, resetAt: now + WINDOW_MS });
+		return next();
+	}
+
+	if (entry.count >= MAX_ATTEMPTS) {
+		const retryAfter = Math.ceil((entry.resetAt - now) / 1000);
+		c.header("Retry-After", String(retryAfter));
+		return c.json({ error: "Too many attempts. Try again later." }, 429);
+	}
+
+	entry.count++;
+	return next();
+}
+```
+
+- [ ] **Step 2: Apply rate limiter to auth routes**
+
+In `src/server/routes/auth.ts`, add the import:
+
+```ts
+import { rateLimit } from "../middleware/rateLimit.ts";
+```
+
+Update the `POST /setup` handler to include the rate limiter:
+
+```ts
+app.post("/setup", rateLimit, zValidator("json", setupSchema), async (c) => {
+```
+
+Update the `POST /login` handler to include the rate limiter:
+
+```ts
+app.post("/login", rateLimit, zValidator("json", loginSchema), async (c) => {
+```
+
+- [ ] **Step 3: Run tests**
+
+Run: `bun test`
+Expected: All 183 tests pass. Auth tests make fewer than 5 requests per endpoint so rate limiting won't trigger.
+
+- [ ] **Step 4: Run lint**
+
+Run: `bun run lint`
+Expected: No errors.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add src/server/middleware/rateLimit.ts src/server/routes/auth.ts
+git commit -m "feat: add rate limiting on login and setup endpoints"
+```
+
+---
+
+### Task 5: Client Error Boundary
+
+**Files:**
+- Modify: `src/client/routes/__root.tsx`
+
+- [ ] **Step 1: Add error boundary component and wire it up**
+
+In `src/client/routes/__root.tsx`, add the import for `useRouter` at the top (add to existing import from `@tanstack/react-router`):
+
+```ts
+import {
+	createRootRoute,
+	Outlet,
+	useMatchRoute,
+	useNavigate,
+	useRouter,
+	type ErrorComponentProps,
+} from "@tanstack/react-router";
+```
+
+Add the `errorComponent` to the route definition:
+
+```ts
+export const Route = createRootRoute({
+	component: RootLayout,
+	errorComponent: RootErrorBoundary,
+});
+```
+
+Add the `RootErrorBoundary` function before `RootLayout`:
+
+```tsx
+function RootErrorBoundary({ error, reset }: ErrorComponentProps) {
+	const router = useRouter();
+
+	return (
+		<div className="min-h-screen bg-gray-50 flex items-center justify-center">
+			<div className="max-w-md mx-auto text-center px-4">
+				<div className="w-12 h-12 bg-red-100 rounded-full flex items-center justify-center mx-auto mb-4">
+					<svg
+						className="w-6 h-6 text-red-600"
+						fill="none"
+						stroke="currentColor"
+						viewBox="0 0 24 24"
+					>
+						<path
+							strokeLinecap="round"
+							strokeLinejoin="round"
+							strokeWidth={2}
+							d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-2.5L13.732 4c-.77-.833-1.964-.833-2.732 0L4.082 16.5c-.77.833.192 2.5 1.732 2.5z"
+						/>
+					</svg>
+				</div>
+				<h1 className="text-xl font-semibold text-gray-900 mb-2">
+					Something went wrong
+				</h1>
+				<p className="text-sm text-gray-500 mb-6">
+					{error instanceof Error ? error.message : "An unexpected error occurred"}
+				</p>
+				<button
+					type="button"
+					onClick={() => {
+						reset();
+						router.invalidate();
+					}}
+					className="px-5 py-2.5 bg-gray-700 hover:bg-gray-800 text-white text-sm font-medium rounded-lg transition-colors"
+				>
+					Try again
+				</button>
+			</div>
+		</div>
+	);
+}
+```
+
+- [ ] **Step 2: Run lint**
+
+Run: `bun run lint`
+Expected: No errors.
+
+- [ ] **Step 3: Run tests**
+
+Run: `bun test`
+Expected: All 183 tests pass.
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add src/client/routes/__root.tsx
+git commit -m "feat: add error boundary to root route for crash resilience"
+```
+
+---
+
+### Task 6: Split Collection Route into Tab Components
+
+**Files:**
+- Create: `src/client/components/CollectionView.tsx`
+- Create: `src/client/components/PlanningView.tsx`
+- Create: `src/client/components/SetupsView.tsx`
+- Modify: `src/client/routes/collection/index.tsx`
+
+- [ ] **Step 1: Create CollectionView component**
+
+Create `src/client/components/CollectionView.tsx` with the `CollectionView` function extracted from `collection/index.tsx` (lines 72-334). The component needs these imports:
+
+```tsx
+import { useMemo, useState } from "react";
+import { CategoryFilterDropdown } from "./CategoryFilterDropdown";
+import { CategoryHeader } from "./CategoryHeader";
+import { ItemCard } from "./ItemCard";
+import { useCategories } from "../hooks/useCategories";
+import { useCurrency } from "../hooks/useCurrency";
+import { useItems } from "../hooks/useItems";
+import { useTotals } from "../hooks/useTotals";
+import { useWeightUnit } from "../hooks/useWeightUnit";
+import { formatPrice, formatWeight } from "../lib/formatters";
+import { LucideIcon } from "../lib/iconData";
+import { useUIStore } from "../stores/uiStore";
+
+export function CollectionView() {
+	// ... exact same function body as lines 73-334 of collection/index.tsx
+}
+```
+
+Copy the entire `CollectionView` function body as-is. No logic changes.
+
+- [ ] **Step 2: Create PlanningView component**
+
+Create `src/client/components/PlanningView.tsx` with the `PlanningView` function extracted from `collection/index.tsx` (lines 337-523):
+
+```tsx
+import { useState } from "react";
+import { CategoryFilterDropdown } from "./CategoryFilterDropdown";
+import { CreateThreadModal } from "./CreateThreadModal";
+import { ThreadCard } from "./ThreadCard";
+import { useCategories } from "../hooks/useCategories";
+import { useThreads } from "../hooks/useThreads";
+import { useUIStore } from "../stores/uiStore";
+
+export function PlanningView() {
+	// ... exact same function body as lines 338-523 of collection/index.tsx
+}
+```
+
+Copy the entire `PlanningView` function body as-is. No logic changes.
+
+- [ ] **Step 3: Create SetupsView component**
+
+Create `src/client/components/SetupsView.tsx` with the `SetupsView` function extracted from `collection/index.tsx` (lines 526-633):
+
+```tsx
+import { useState } from "react";
+import { SetupCard } from "./SetupCard";
+import { useCreateSetup, useSetups } from "../hooks/useSetups";
+
+export function SetupsView() {
+	// ... exact same function body as lines 527-633 of collection/index.tsx
+}
+```
+
+Copy the entire `SetupsView` function body as-is. No logic changes.
+
+- [ ] **Step 4: Update collection/index.tsx**
+
+Replace the entire file content. Keep only the route definition, tab switching logic, animation constants, and imports from the new components:
+
+```tsx
+import { createFileRoute } from "@tanstack/react-router";
+import { AnimatePresence, motion } from "framer-motion";
+import { useRef } from "react";
+import { z } from "zod";
+import { CollectionView } from "../../components/CollectionView";
+import { PlanningView } from "../../components/PlanningView";
+import { SetupsView } from "../../components/SetupsView";
+
+const searchSchema = z.object({
+	tab: z.enum(["gear", "planning", "setups"]).catch("gear"),
+});
+
+export const Route = createFileRoute("/collection/")({
+	validateSearch: searchSchema,
+	component: CollectionPage,
+});
+
+const TAB_ORDER = ["gear", "planning", "setups"] as const;
+
+const slideVariants = {
+	enter: (dir: number) => ({ x: `${dir * 15}%`, opacity: 0 }),
+	center: { x: 0, opacity: 1 },
+	exit: (dir: number) => ({ x: `${dir * -15}%`, opacity: 0 }),
+};
+
+function CollectionPage() {
+	const { tab } = Route.useSearch();
+	const prevTab = useRef(tab);
+
+	const direction =
+		TAB_ORDER.indexOf(tab) >= TAB_ORDER.indexOf(prevTab.current) ? 1 : -1;
+	prevTab.current = tab;
+
+	return (
+		<div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-6 overflow-x-hidden">
+			<AnimatePresence mode="wait" initial={false} custom={direction}>
+				<motion.div
+					key={tab}
+					custom={direction}
+					variants={slideVariants}
+					initial="enter"
+					animate="center"
+					exit="exit"
+					transition={{ duration: 0.12, ease: "easeInOut" }}
+				>
+					{tab === "gear" ? (
+						<CollectionView />
+					) : tab === "planning" ? (
+						<PlanningView />
+					) : (
+						<SetupsView />
+					)}
+				</motion.div>
+			</AnimatePresence>
+		</div>
+	);
+}
+```
+
+- [ ] **Step 5: Run lint**
+
+Run: `bun run lint`
+Expected: No errors. (Biome may flag import organization — fix if needed.)
+
+- [ ] **Step 6: Run tests**
+
+Run: `bun test`
+Expected: All 183 tests pass.
+
+- [ ] **Step 7: Commit**
+
+```bash
+git add src/client/components/CollectionView.tsx src/client/components/PlanningView.tsx src/client/components/SetupsView.tsx src/client/routes/collection/index.tsx
+git commit -m "refactor: extract tab views from collection route into separate components"
+```
+
+---
+
+### Task 7: Docs Cleanup
+
+**Files:**
+- Modify: `.planning/PROJECT.md:84`
+
+- [ ] **Step 1: Update stale constraint**
+
+In `.planning/PROJECT.md`, change line 84 from:
+
+```
+- **Scope**: No auth, single user for v1
+```
+
+to:
+
+```
+- **Scope**: Single user with cookie/API key auth
+```
+
+- [ ] **Step 2: Commit**
+
+```bash
+git add .planning/PROJECT.md
+git commit -m "docs: update PROJECT.md constraints to reflect auth implementation"
+```
+
+---
+
+### Task 8: Final Verification
+
+- [ ] **Step 1: Run full test suite**
+
+Run: `bun test`
+Expected: All 183 tests pass.
+
+- [ ] **Step 2: Run lint**
+
+Run: `bun run lint`
+Expected: No errors.
+
+- [ ] **Step 3: Verify dev server starts**
+
+Run: `bun run dev:server &` then `curl http://localhost:3000/api/health`
+Expected: `{"status":"ok"}`
+Then kill the background server.

docs/superpowers/plans/2026-04-03-testing-improvements.md

@@ -0,0 +1,934 @@
+# Testing Improvements Implementation Plan
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Add unit tests for new server code (parseId, rate limiter, param validation routes), set up Playwright E2E testing with a seeded database, and write E2E tests covering dashboard, collection, threads, auth, and error handling.
+
+**Architecture:** Unit tests use existing Bun test runner + Hono `app.request()` pattern. E2E tests use Playwright against a real server with a pre-seeded SQLite database. A global-setup script creates the test DB using Drizzle migrations + direct inserts before Playwright runs.
+
+**Tech Stack:** Bun test runner, Playwright (Chromium only), Drizzle ORM migrations, Hono
+
+---
+
+### Task 1: Unit Tests for parseId
+
+**Files:**
+- Create: `tests/lib/params.test.ts`
+
+- [ ] **Step 1: Write tests**
+
+Create `tests/lib/params.test.ts`:
+
+```ts
+import { describe, expect, it } from "bun:test";
+import { parseId } from "../../src/server/lib/params";
+
+describe("parseId", () => {
+	it("returns number for valid positive integers", () => {
+		expect(parseId("1")).toBe(1);
+		expect(parseId("42")).toBe(42);
+		expect(parseId("999")).toBe(999);
+	});
+
+	it("returns null for zero", () => {
+		expect(parseId("0")).toBeNull();
+	});
+
+	it("returns null for negative numbers", () => {
+		expect(parseId("-1")).toBeNull();
+		expect(parseId("-100")).toBeNull();
+	});
+
+	it("returns null for decimals", () => {
+		expect(parseId("1.5")).toBeNull();
+		expect(parseId("3.14")).toBeNull();
+	});
+
+	it("returns null for non-numeric strings", () => {
+		expect(parseId("abc")).toBeNull();
+		expect(parseId("")).toBeNull();
+		expect(parseId("hello")).toBeNull();
+		expect(parseId("12abc")).toBeNull();
+	});
+
+	it("returns null for special values", () => {
+		expect(parseId("NaN")).toBeNull();
+		expect(parseId("Infinity")).toBeNull();
+		expect(parseId("-Infinity")).toBeNull();
+	});
+});
+```
+
+- [ ] **Step 2: Run tests**
+
+Run: `bun test tests/lib/params.test.ts`
+Expected: All tests pass.
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add tests/lib/params.test.ts
+git commit -m "test: add unit tests for parseId helper"
+```
+
+---
+
+### Task 2: Unit Tests for Rate Limiter
+
+**Files:**
+- Modify: `src/server/middleware/rateLimit.ts` (add test reset function)
+- Create: `tests/middleware/rateLimit.test.ts`
+
+- [ ] **Step 1: Add test reset function to rate limiter**
+
+In `src/server/middleware/rateLimit.ts`, add at the end of the file:
+
+```ts
+/** @internal — only for testing */
+export function _resetForTesting() {
+	store.clear();
+}
+```
+
+- [ ] **Step 2: Write tests**
+
+Create `tests/middleware/rateLimit.test.ts`:
+
+```ts
+import { beforeEach, describe, expect, it } from "bun:test";
+import { Hono } from "hono";
+import { _resetForTesting, rateLimit } from "../../src/server/middleware/rateLimit";
+
+function createApp() {
+	const app = new Hono();
+	app.post("/login", rateLimit, (c) => c.json({ ok: true }));
+	app.post("/setup", rateLimit, (c) => c.json({ ok: true }));
+	return app;
+}
+
+function makeRequest(app: Hono, path: string, ip = "127.0.0.1") {
+	return app.request(path, {
+		method: "POST",
+		headers: { "x-forwarded-for": ip },
+	});
+}
+
+describe("rateLimit middleware", () => {
+	beforeEach(() => {
+		_resetForTesting();
+	});
+
+	it("allows first request through", async () => {
+		const app = createApp();
+		const res = await makeRequest(app, "/login");
+		expect(res.status).toBe(200);
+	});
+
+	it("allows up to 5 requests", async () => {
+		const app = createApp();
+		for (let i = 0; i < 5; i++) {
+			const res = await makeRequest(app, "/login");
+			expect(res.status).toBe(200);
+		}
+	});
+
+	it("returns 429 after 5 requests", async () => {
+		const app = createApp();
+		for (let i = 0; i < 5; i++) {
+			await makeRequest(app, "/login");
+		}
+		const res = await makeRequest(app, "/login");
+		expect(res.status).toBe(429);
+		const body = await res.json();
+		expect(body.error).toBe("Too many attempts. Try again later.");
+	});
+
+	it("includes Retry-After header on 429", async () => {
+		const app = createApp();
+		for (let i = 0; i < 5; i++) {
+			await makeRequest(app, "/login");
+		}
+		const res = await makeRequest(app, "/login");
+		expect(res.status).toBe(429);
+		const retryAfter = res.headers.get("Retry-After");
+		expect(retryAfter).toBeTruthy();
+		expect(Number(retryAfter)).toBeGreaterThan(0);
+	});
+
+	it("tracks different IPs independently", async () => {
+		const app = createApp();
+		// Fill up IP 1
+		for (let i = 0; i < 5; i++) {
+			await makeRequest(app, "/login", "10.0.0.1");
+		}
+		// IP 1 is blocked
+		const blocked = await makeRequest(app, "/login", "10.0.0.1");
+		expect(blocked.status).toBe(429);
+
+		// IP 2 still works
+		const allowed = await makeRequest(app, "/login", "10.0.0.2");
+		expect(allowed.status).toBe(200);
+	});
+
+	it("tracks different paths independently", async () => {
+		const app = createApp();
+		// Fill up /login
+		for (let i = 0; i < 5; i++) {
+			await makeRequest(app, "/login");
+		}
+		const blockedLogin = await makeRequest(app, "/login");
+		expect(blockedLogin.status).toBe(429);
+
+		// /setup still works
+		const allowedSetup = await makeRequest(app, "/setup");
+		expect(allowedSetup.status).toBe(200);
+	});
+});
+```
+
+- [ ] **Step 3: Run tests**
+
+Run: `bun test tests/middleware/rateLimit.test.ts`
+Expected: All tests pass.
+
+- [ ] **Step 4: Run full test suite**
+
+Run: `bun test`
+Expected: All tests pass (previous 183 + new ones).
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add src/server/middleware/rateLimit.ts tests/middleware/rateLimit.test.ts
+git commit -m "test: add unit tests for rate limiter middleware"
+```
+
+---
+
+### Task 3: Route-Level Tests for Invalid ID Params
+
+**Files:**
+- Create: `tests/routes/params.test.ts`
+
+- [ ] **Step 1: Write tests**
+
+Create `tests/routes/params.test.ts`:
+
+```ts
+import { beforeEach, describe, expect, it } from "bun:test";
+import { Hono } from "hono";
+import { categoryRoutes } from "../../src/server/routes/categories";
+import { itemRoutes } from "../../src/server/routes/items";
+import { setupRoutes } from "../../src/server/routes/setups";
+import { threadRoutes } from "../../src/server/routes/threads";
+import { createTestDb } from "../helpers/db";
+
+function createTestApp() {
+	const db = createTestDb();
+	const app = new Hono();
+	app.use("*", async (c, next) => {
+		c.set("db", db);
+		await next();
+	});
+	app.route("/api/items", itemRoutes);
+	app.route("/api/categories", categoryRoutes);
+	app.route("/api/threads", threadRoutes);
+	app.route("/api/setups", setupRoutes);
+	return app;
+}
+
+describe("Invalid ID parameter handling", () => {
+	let app: Hono;
+
+	beforeEach(() => {
+		app = createTestApp();
+	});
+
+	describe("items", () => {
+		it("GET /api/items/abc returns 400", async () => {
+			const res = await app.request("/api/items/abc");
+			expect(res.status).toBe(400);
+			const body = await res.json();
+			expect(body.error).toContain("Invalid");
+		});
+
+		it("GET /api/items/0 returns 400", async () => {
+			const res = await app.request("/api/items/0");
+			expect(res.status).toBe(400);
+		});
+
+		it("GET /api/items/-1 returns 400", async () => {
+			const res = await app.request("/api/items/-1");
+			expect(res.status).toBe(400);
+		});
+	});
+
+	describe("categories", () => {
+		it("DELETE /api/categories/abc returns 400", async () => {
+			const res = await app.request("/api/categories/abc", {
+				method: "DELETE",
+			});
+			expect(res.status).toBe(400);
+		});
+	});
+
+	describe("threads", () => {
+		it("GET /api/threads/abc returns 400", async () => {
+			const res = await app.request("/api/threads/abc");
+			expect(res.status).toBe(400);
+		});
+
+		it("GET /api/threads/1.5 returns 400", async () => {
+			const res = await app.request("/api/threads/1.5");
+			expect(res.status).toBe(400);
+		});
+	});
+
+	describe("setups", () => {
+		it("GET /api/setups/abc returns 400", async () => {
+			const res = await app.request("/api/setups/abc");
+			expect(res.status).toBe(400);
+		});
+
+		it("GET /api/setups/0 returns 400", async () => {
+			const res = await app.request("/api/setups/0");
+			expect(res.status).toBe(400);
+		});
+	});
+});
+```
+
+- [ ] **Step 2: Run tests**
+
+Run: `bun test tests/routes/params.test.ts`
+Expected: All tests pass.
+
+- [ ] **Step 3: Commit**
+
+```bash
+git add tests/routes/params.test.ts
+git commit -m "test: add route-level tests for invalid ID parameter handling"
+```
+
+---
+
+### Task 4: Install Playwright and Create Config
+
+**Files:**
+- Modify: `package.json` (add dep + scripts)
+- Create: `playwright.config.ts`
+- Modify: `.gitignore`
+
+- [ ] **Step 1: Install Playwright**
+
+```bash
+bun add -d @playwright/test
+bunx playwright install chromium
+```
+
+- [ ] **Step 2: Create playwright.config.ts**
+
+Create `playwright.config.ts` at project root:
+
+```ts
+import { defineConfig, devices } from "@playwright/test";
+
+export default defineConfig({
+	testDir: "./e2e",
+	fullyParallel: false,
+	retries: 0,
+	workers: 1,
+	reporter: "list",
+	globalSetup: "./e2e/global-setup.ts",
+	use: {
+		baseURL: "http://localhost:3000",
+		trace: "on-first-retry",
+	},
+	projects: [
+		{
+			name: "chromium",
+			use: { ...devices["Desktop Chrome"] },
+		},
+	],
+	webServer: {
+		command: "DATABASE_PATH=./e2e/test.db bun run dev:server",
+		port: 3000,
+		reuseExistingServer: !process.env.CI,
+		timeout: 10000,
+	},
+});
+```
+
+- [ ] **Step 3: Add scripts to package.json**
+
+Add these to the `"scripts"` section in `package.json`:
+
+```json
+"test:e2e": "bunx playwright test",
+"test:e2e:ui": "bunx playwright test --ui"
+```
+
+- [ ] **Step 4: Update .gitignore**
+
+Append to `.gitignore`:
+
+```
+# Playwright
+e2e/test.db
+test-results/
+playwright-report/
+```
+
+- [ ] **Step 5: Run lint**
+
+Run: `bun run lint`
+Expected: Clean.
+
+- [ ] **Step 6: Commit**
+
+```bash
+git add package.json bun.lock playwright.config.ts .gitignore
+git commit -m "chore: install Playwright and add E2E test configuration"
+```
+
+---
+
+### Task 5: E2E Database Seed and Global Setup
+
+**Files:**
+- Create: `e2e/seed.ts`
+- Create: `e2e/global-setup.ts`
+
+- [ ] **Step 1: Create seed script**
+
+Create `e2e/seed.ts`:
+
+```ts
+import { Database } from "bun:sqlite";
+import { drizzle } from "drizzle-orm/bun-sqlite";
+import { migrate } from "drizzle-orm/bun-sqlite/migrator";
+import * as schema from "../src/db/schema";
+
+const DB_PATH = "./e2e/test.db";
+
+export async function seedTestDatabase() {
+	// Remove old test DB if it exists
+	try {
+		await Bun.file(DB_PATH).exists() &&
+			(await import("node:fs/promises")).then((fs) => fs.unlink(DB_PATH));
+	} catch {
+		// File doesn't exist, that's fine
+	}
+
+	const sqlite = new Database(DB_PATH);
+	sqlite.run("PRAGMA journal_mode = WAL");
+	sqlite.run("PRAGMA foreign_keys = ON");
+
+	const db = drizzle(sqlite, { schema });
+
+	// Apply all migrations
+	migrate(db, { migrationsFolder: "./drizzle" });
+
+	// ── Seed Categories ──
+	const [uncategorized] = db
+		.insert(schema.categories)
+		.values({ name: "Uncategorized", icon: "package" })
+		.returning()
+		.all();
+
+	const [shelter] = db
+		.insert(schema.categories)
+		.values({ name: "Shelter", icon: "tent" })
+		.returning()
+		.all();
+
+	const [sleep] = db
+		.insert(schema.categories)
+		.values({ name: "Sleep System", icon: "moon" })
+		.returning()
+		.all();
+
+	const [cook] = db
+		.insert(schema.categories)
+		.values({ name: "Cook Kit", icon: "flame" })
+		.returning()
+		.all();
+
+	// ── Seed Items ──
+	const tent = db
+		.insert(schema.items)
+		.values({
+			name: "Zpacks Duplex",
+			weightGrams: 539,
+			priceCents: 67900,
+			categoryId: shelter.id,
+			notes: "DCF shelter, 2-person",
+		})
+		.returning()
+		.get();
+
+	const tarp = db
+		.insert(schema.items)
+		.values({
+			name: "Borah Gear Tarp",
+			weightGrams: 156,
+			priceCents: 11000,
+			categoryId: shelter.id,
+		})
+		.returning()
+		.get();
+
+	const quilt = db
+		.insert(schema.items)
+		.values({
+			name: "Enlightened Equipment Enigma 20",
+			weightGrams: 595,
+			priceCents: 34000,
+			categoryId: sleep.id,
+			notes: "20F quilt",
+		})
+		.returning()
+		.get();
+
+	const pad = db
+		.insert(schema.items)
+		.values({
+			name: "Therm-a-Rest NeoAir XLite",
+			weightGrams: 354,
+			priceCents: 20999,
+			categoryId: sleep.id,
+		})
+		.returning()
+		.get();
+
+	const stove = db
+		.insert(schema.items)
+		.values({
+			name: "BRS-3000T Stove",
+			weightGrams: 25,
+			priceCents: 2000,
+			categoryId: cook.id,
+		})
+		.returning()
+		.get();
+
+	const pot = db
+		.insert(schema.items)
+		.values({
+			name: "Toaks 750ml Pot",
+			weightGrams: 103,
+			priceCents: 3000,
+			categoryId: cook.id,
+		})
+		.returning()
+		.get();
+
+	// ── Seed Active Thread with 3 Candidates ──
+	const activeThread = db
+		.insert(schema.threads)
+		.values({
+			name: "New Backpack",
+			status: "active",
+			categoryId: uncategorized.id,
+		})
+		.returning()
+		.get();
+
+	db.insert(schema.threadCandidates)
+		.values({
+			threadId: activeThread.id,
+			name: "ULA Circuit",
+			weightGrams: 1077,
+			priceCents: 27500,
+			categoryId: uncategorized.id,
+			pros: "Great hip belt\nLarge capacity",
+			cons: "Heavier than competitors",
+			sortOrder: 1000,
+			status: "researching",
+		})
+		.run();
+
+	db.insert(schema.threadCandidates)
+		.values({
+			threadId: activeThread.id,
+			name: "Gossamer Gear Mariposa",
+			weightGrams: 737,
+			priceCents: 28500,
+			categoryId: uncategorized.id,
+			pros: "Very lightweight\nGood ventilation",
+			cons: "Smaller hip belt pockets",
+			sortOrder: 2000,
+			status: "researching",
+		})
+		.run();
+
+	db.insert(schema.threadCandidates)
+		.values({
+			threadId: activeThread.id,
+			name: "Granite Gear Crown2 38",
+			weightGrams: 850,
+			priceCents: 18000,
+			categoryId: uncategorized.id,
+			sortOrder: 3000,
+			status: "ordered",
+		})
+		.run();
+
+	// ── Seed Resolved Thread ──
+	const resolvedThread = db
+		.insert(schema.threads)
+		.values({
+			name: "Camp Stove",
+			status: "resolved",
+			categoryId: cook.id,
+			resolvedCandidateId: 1,
+		})
+		.returning()
+		.get();
+
+	db.insert(schema.threadCandidates)
+		.values({
+			threadId: resolvedThread.id,
+			name: "BRS-3000T",
+			weightGrams: 25,
+			priceCents: 2000,
+			categoryId: cook.id,
+			sortOrder: 1000,
+			status: "arrived",
+		})
+		.run();
+
+	// ── Seed Setup with Items ──
+	const setup = db
+		.insert(schema.setups)
+		.values({ name: "Weekend Overnighter" })
+		.returning()
+		.get();
+
+	db.insert(schema.setupItems)
+		.values([
+			{ setupId: setup.id, itemId: tent.id, classification: "base" },
+			{ setupId: setup.id, itemId: quilt.id, classification: "base" },
+			{ setupId: setup.id, itemId: pad.id, classification: "base" },
+			{ setupId: setup.id, itemId: stove.id, classification: "consumable" },
+		])
+		.run();
+
+	// ── Seed User ──
+	const passwordHash = await Bun.password.hash("password123");
+	db.insert(schema.users)
+		.values({ username: "admin", passwordHash })
+		.run();
+
+	// ── Seed Settings ──
+	db.insert(schema.settings)
+		.values([
+			{ key: "weightUnit", value: "g" },
+			{ key: "currency", value: "USD" },
+			{ key: "onboardingComplete", value: "true" },
+		])
+		.run();
+
+	sqlite.close();
+	console.log("E2E test database seeded at", DB_PATH);
+}
+```
+
+- [ ] **Step 2: Create global-setup**
+
+Create `e2e/global-setup.ts`:
+
+```ts
+import { seedTestDatabase } from "./seed";
+
+export default async function globalSetup() {
+	await seedTestDatabase();
+}
+```
+
+- [ ] **Step 3: Verify seed works**
+
+Run: `bun run e2e/global-setup.ts`
+Expected: Prints "E2E test database seeded at ./e2e/test.db" and the file exists.
+
+Then clean up: `rm -f e2e/test.db`
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add e2e/seed.ts e2e/global-setup.ts
+git commit -m "test: add E2E database seed and Playwright global setup"
+```
+
+---
+
+### Task 6: E2E Tests — Dashboard and Collection
+
+**Files:**
+- Create: `e2e/dashboard.spec.ts`
+- Create: `e2e/collection.spec.ts`
+
+- [ ] **Step 1: Create dashboard tests**
+
+Create `e2e/dashboard.spec.ts`:
+
+```ts
+import { expect, test } from "@playwright/test";
+
+test.describe("Dashboard", () => {
+	test("loads and shows summary cards", async ({ page }) => {
+		await page.goto("/");
+		await expect(page.locator("text=GearBox")).toBeVisible();
+		// Should show item count (we seeded 6 items)
+		await expect(page.locator("text=6")).toBeVisible();
+	});
+
+	test("has navigation to collection", async ({ page }) => {
+		await page.goto("/");
+		// Click on a dashboard card or link that goes to collection
+		const collectionLink = page.locator('a[href*="collection"]').first();
+		if (await collectionLink.isVisible()) {
+			await collectionLink.click();
+			await expect(page).toHaveURL(/collection/);
+		}
+	});
+});
+```
+
+- [ ] **Step 2: Create collection tests**
+
+Create `e2e/collection.spec.ts`:
+
+```ts
+import { expect, test } from "@playwright/test";
+
+test.describe("Collection", () => {
+	test("gear tab shows items grouped by category", async ({ page }) => {
+		await page.goto("/collection?tab=gear");
+		// Should see seeded items
+		await expect(page.locator("text=Zpacks Duplex")).toBeVisible();
+		await expect(page.locator("text=BRS-3000T Stove")).toBeVisible();
+		// Should see category headers
+		await expect(page.locator("text=Shelter")).toBeVisible();
+		await expect(page.locator("text=Cook Kit")).toBeVisible();
+	});
+
+	test("search filters items by name", async ({ page }) => {
+		await page.goto("/collection?tab=gear");
+		const searchInput = page.locator('input[placeholder*="Search"]');
+		await searchInput.fill("Zpacks");
+		// Should show matching item
+		await expect(page.locator("text=Zpacks Duplex")).toBeVisible();
+		// Should hide non-matching items
+		await expect(page.locator("text=BRS-3000T Stove")).not.toBeVisible();
+	});
+
+	test("tab switching works", async ({ page }) => {
+		await page.goto("/collection?tab=gear");
+		await expect(page.locator("text=Zpacks Duplex")).toBeVisible();
+
+		// Switch to planning tab
+		await page.goto("/collection?tab=planning");
+		await expect(page.locator("text=Planning Threads")).toBeVisible();
+		await expect(page.locator("text=New Backpack")).toBeVisible();
+
+		// Switch to setups tab
+		await page.goto("/collection?tab=setups");
+		await expect(page.locator("text=Weekend Overnighter")).toBeVisible();
+	});
+
+	test("category filter dropdown works", async ({ page }) => {
+		await page.goto("/collection?tab=gear");
+		// Open category filter
+		const filterButton = page.locator("text=All categories");
+		await filterButton.click();
+		// Select "Shelter"
+		await page.locator("li").filter({ hasText: "Shelter" }).click();
+		// Should show only shelter items
+		await expect(page.locator("text=Zpacks Duplex")).toBeVisible();
+		await expect(page.locator("text=BRS-3000T Stove")).not.toBeVisible();
+	});
+});
+```
+
+- [ ] **Step 3: Run E2E tests**
+
+Run: `bun run test:e2e`
+Expected: All tests pass. If any fail due to selector issues, adjust selectors based on actual DOM.
+
+- [ ] **Step 4: Commit**
+
+```bash
+git add e2e/dashboard.spec.ts e2e/collection.spec.ts
+git commit -m "test: add E2E tests for dashboard and collection views"
+```
+
+---
+
+### Task 7: E2E Tests — Threads, Auth, Error Handling
+
+**Files:**
+- Create: `e2e/threads.spec.ts`
+- Create: `e2e/auth.spec.ts`
+- Create: `e2e/error-handling.spec.ts`
+
+- [ ] **Step 1: Create threads tests**
+
+Create `e2e/threads.spec.ts`:
+
+```ts
+import { expect, test } from "@playwright/test";
+
+test.describe("Threads", () => {
+	test("thread detail page shows candidates", async ({ page }) => {
+		// Navigate to the active thread
+		await page.goto("/collection?tab=planning");
+		await page.locator("text=New Backpack").click();
+		// Should see candidates
+		await expect(page.locator("text=ULA Circuit")).toBeVisible();
+		await expect(page.locator("text=Gossamer Gear Mariposa")).toBeVisible();
+		await expect(page.locator("text=Granite Gear Crown2 38")).toBeVisible();
+	});
+
+	test("rank badges are visible on candidates", async ({ page }) => {
+		await page.goto("/collection?tab=planning");
+		await page.locator("text=New Backpack").click();
+		// Should see rank badges (gold, silver, bronze for top 3)
+		// The rank badges use specific colors: #D4AF37 (gold), #C0C0C0 (silver), #CD7F32 (bronze)
+		await expect(page.locator("text=#1").first()).toBeVisible();
+	});
+
+	test("comparison view toggles on", async ({ page }) => {
+		await page.goto("/collection?tab=planning");
+		await page.locator("text=New Backpack").click();
+		// Find and click the compare toggle
+		const compareButton = page.locator("button", { hasText: /compare/i });
+		if (await compareButton.isVisible()) {
+			await compareButton.click();
+			// Comparison table should appear with attribute rows
+			await expect(page.locator("text=Weight")).toBeVisible();
+			await expect(page.locator("text=Price")).toBeVisible();
+		}
+	});
+
+	test("resolved thread shows winner", async ({ page }) => {
+		await page.goto("/collection?tab=planning");
+		// Switch to resolved tab
+		await page.locator("button", { hasText: "Resolved" }).click();
+		await page.locator("text=Camp Stove").click();
+		// Should indicate resolved state
+		await expect(page.locator("text=BRS-3000T")).toBeVisible();
+	});
+});
+```
+
+- [ ] **Step 2: Create auth tests**
+
+Create `e2e/auth.spec.ts`:
+
+```ts
+import { expect, test } from "@playwright/test";
+
+test.describe("Auth", () => {
+	test("login page renders", async ({ page }) => {
+		await page.goto("/login");
+		await expect(page.locator("text=Log in")).toBeVisible();
+	});
+
+	test("login with valid credentials succeeds", async ({ page }) => {
+		await page.goto("/login");
+		await page.locator('input[name="username"], input[placeholder*="sername"]').fill("admin");
+		await page.locator('input[type="password"]').fill("password123");
+		await page.locator('button[type="submit"]').click();
+		// Should redirect away from login
+		await page.waitForURL((url) => !url.pathname.includes("/login"), {
+			timeout: 5000,
+		});
+	});
+
+	test("login with wrong password shows error", async ({ page }) => {
+		await page.goto("/login");
+		await page.locator('input[name="username"], input[placeholder*="sername"]').fill("admin");
+		await page.locator('input[type="password"]').fill("wrongpassword");
+		await page.locator('button[type="submit"]').click();
+		// Should show error message
+		await expect(page.locator("text=Invalid credentials").or(page.locator('[role="alert"]'))).toBeVisible({
+			timeout: 3000,
+		});
+	});
+});
+```
+
+- [ ] **Step 3: Create error handling tests**
+
+Create `e2e/error-handling.spec.ts`:
+
+```ts
+import { expect, test } from "@playwright/test";
+
+test.describe("Error handling", () => {
+	test("non-existent thread shows not found or error", async ({ page }) => {
+		await page.goto("/threads/99999");
+		// Should not white-screen — should show some content
+		const body = page.locator("body");
+		await expect(body).not.toBeEmpty();
+		// Either shows error boundary or "not found" text
+		const hasContent = await page
+			.locator("text=Something went wrong")
+			.or(page.locator("text=not found"))
+			.or(page.locator("text=Not Found"))
+			.isVisible()
+			.catch(() => false);
+		// At minimum, the page should not be blank
+		const bodyText = await body.textContent();
+		expect(bodyText?.length).toBeGreaterThan(0);
+	});
+
+	test("non-existent setup shows not found or error", async ({ page }) => {
+		await page.goto("/setups/99999");
+		const body = page.locator("body");
+		await expect(body).not.toBeEmpty();
+		const bodyText = await body.textContent();
+		expect(bodyText?.length).toBeGreaterThan(0);
+	});
+
+	test("app recovers from navigation errors", async ({ page }) => {
+		// Navigate to a bad route, then back to a good one
+		await page.goto("/threads/99999");
+		await page.goto("/");
+		// Dashboard should load fine
+		await expect(page.locator("text=GearBox")).toBeVisible();
+	});
+});
+```
+
+- [ ] **Step 4: Run all E2E tests**
+
+Run: `bun run test:e2e`
+Expected: All tests pass.
+
+- [ ] **Step 5: Commit**
+
+```bash
+git add e2e/threads.spec.ts e2e/auth.spec.ts e2e/error-handling.spec.ts
+git commit -m "test: add E2E tests for threads, auth, and error handling"
+```
+
+---
+
+### Task 8: Final Verification
+
+- [ ] **Step 1: Run unit tests**
+
+Run: `bun test`
+Expected: All tests pass (previous 183 + new parseId + rate limiter + param routes).
+
+- [ ] **Step 2: Run E2E tests**
+
+Run: `bun run test:e2e`
+Expected: All E2E tests pass.
+
+- [ ] **Step 3: Run lint**
+
+Run: `bun run lint`
+Expected: Clean.

docs/superpowers/specs/2026-04-03-code-quality-round2-design.md

@@ -0,0 +1,74 @@
+# Code Quality Improvements (Round 2) Design
+
+**Date:** 2026-04-03
+**Scope:** Combined formatters hook, test helper schema generation, stale todo cleanup
+
+## 1. useFormatters Combined Hook
+
+**Problem:** 14 component files import the same 3-4 lines: `useWeightUnit`, `useCurrency`, `formatWeight`, `formatPrice`. This is repetitive boilerplate.
+
+**Solution:** Create `src/client/hooks/useFormatters.ts` that returns pre-bound formatting functions:
+
+```ts
+export function useFormatters() {
+  const unit = useWeightUnit();
+  const currency = useCurrency();
+  return {
+    weight: (grams: number | null) => formatWeight(grams, unit),
+    price: (cents: number | null) => formatPrice(cents, currency),
+    unit,
+    currency,
+  };
+}
+```
+
+**Consumer files to update (14):**
+- CollectionView.tsx
+- setups/$setupId.tsx
+- routes/index.tsx
+- WeightSummaryCard.tsx
+- TotalsBar.tsx
+- settings.tsx
+- ThreadCard.tsx
+- SetupCard.tsx
+- ItemPicker.tsx
+- ItemCard.tsx
+- ComparisonTable.tsx
+- CandidateCard.tsx
+- CandidateListItem.tsx
+- CategoryHeader.tsx
+
+Each file replaces 3-4 imports + 2 hook calls with 1 import + 1 destructured hook call. Components that need raw `unit` or `currency` (e.g., WeightSummaryCard uses `unit` as a type, TotalsBar has a unit toggle) get them from the return object.
+
+## 2. Test Helper Schema Generation
+
+**Problem:** `tests/helpers/db.ts` has 120 lines of hand-written CREATE TABLE SQL that must manually mirror `src/db/schema.ts`. Any schema change requires updating both files — a known source of `SqliteError: no such column` failures.
+
+**Solution:** Replace hand-written SQL with Drizzle's migration runner:
+
+```ts
+import { migrate } from "drizzle-orm/bun-sqlite/migrator";
+
+export function createTestDb() {
+  const sqlite = new Database(":memory:");
+  sqlite.run("PRAGMA foreign_keys = ON");
+  const db = drizzle(sqlite, { schema });
+  migrate(db, { migrationsFolder: "./drizzle" });
+  db.insert(schema.categories).values({ name: "Uncategorized", icon: "package" }).run();
+  return db;
+}
+```
+
+This reduces the file from ~128 lines to ~15 lines and eliminates all future manual sync.
+
+## 3. Stale Todo Cleanup
+
+**Problem:** Pending todo "Replace planning category filter select with icon-aware dropdown" from 2026-03-15 is already resolved — `PlanningView.tsx` uses `<CategoryFilterDropdown>` which renders Lucide icons.
+
+**Solution:** Move the todo file from `pending/` to `done/`.
+
+## Commit Strategy
+
+1. **useFormatters hook** — create hook + update all 14 consumer files
+2. **Test helper migration** — replace hand-written SQL with migrate()
+3. **Todo cleanup** — move stale todo to done

docs/superpowers/specs/2026-04-03-codebase-improvements-design.md

@@ -0,0 +1,152 @@
+# Codebase Improvements Design
+
+**Date:** 2026-04--03
+**Scope:** General code quality, error handling, resilience, and maintainability improvements
+
+## 1. Server Hardening
+
+### 1a. Explicit DB Context Middleware
+
+**File:** `src/server/index.ts`
+
+Add middleware that explicitly sets `c.set("db", prodDb)` for all API routes. Currently routes call `c.get("db")` but nothing sets it in production — services silently fall back to `prodDb` via default parameters. This makes production behavior match the test pattern.
+
+```ts
+import { db as prodDb } from "../db/index.ts";
+
+app.use("/api/*", async (c, next) => {
+  c.set("db", prodDb);
+  return next();
+});
+```
+
+Place this **before** the auth middleware so `db` is available when auth checks run.
+
+### 1b. Route Parameter Validation
+
+**New file:** `src/server/lib/params.ts`
+
+Create a helper that validates numeric route params:
+
+```ts
+export function parseId(raw: string): number | null {
+  const id = Number(raw);
+  if (!Number.isInteger(id) || id <= 0) return null;
+  return id;
+}
+```
+
+Update all route files (`items.ts`, `threads.ts`, `categories.ts`, `setups.ts`) to replace `Number(c.req.param("id"))` with `parseId()`, returning 400 for invalid IDs.
+
+### 1c. Centralized Error Handling
+
+**File:** `src/server/index.ts`
+
+Add Hono's `onError` handler:
+
+```ts
+app.onError((err, c) => {
+  console.error(`[${c.req.method}] ${c.req.path}:`, err);
+  const status = err instanceof HTTPException ? err.status : 500;
+  const message = process.env.NODE_ENV === "production"
+    ? "Internal server error"
+    : err.message;
+  return c.json({ error: message }, status);
+});
+```
+
+### 1d. Auth Comment Fix
+
+**File:** `src/server/index.ts`
+
+Change comment from:
+```
+// Auth middleware for write operations (POST/PUT/DELETE) on non-auth routes
+```
+To:
+```
+// Auth middleware for write operations (POST/PUT/PATCH/DELETE) on non-auth routes
+```
+
+### 1e. Rate Limiting on Auth Endpoints
+
+**New file:** `src/server/middleware/rateLimit.ts`
+
+In-memory rate limiter using a `Map<string, { count: number; resetAt: number }>`:
+
+- Tracks by IP (`c.req.header("x-forwarded-for") || "unknown"`)
+- 5 attempts per 15-minute window
+- Returns 429 with `{ error: "Too many attempts. Try again later." }` and `Retry-After` header
+- Stale entries cleaned on each check
+- Applied to `POST /api/auth/login` and `POST /api/auth/setup`
+
+## 2. Client Resilience
+
+### Error Boundary
+
+**File:** `src/client/routes/__root.tsx`
+
+Add `errorComponent` to the root route definition:
+
+```ts
+export const Route = createRootRoute({
+  component: RootLayout,
+  errorComponent: RootErrorBoundary,
+});
+```
+
+`RootErrorBoundary` renders a centered error message with:
+- "Something went wrong" heading
+- Error message in dev mode
+- "Try again" button that calls `router.invalidate()` + `reset()`
+
+Uses TanStack Router's `ErrorComponentProps` which provides `error` and `reset`.
+
+## 3. Client Refactor
+
+### Split collection/index.tsx
+
+Extract the three tab-level functions into separate component files:
+
+| Source function | New file | Approx lines |
+|----------------|----------|-------------|
+| `CollectionView()` | `src/client/components/CollectionView.tsx` | ~260 |
+| `PlanningView()` | `src/client/components/PlanningView.tsx` | ~190 |
+| `SetupsView()` | `src/client/components/SetupsView.tsx` | ~110 |
+
+`collection/index.tsx` keeps:
+- Route definition with `searchSchema` and `validateSearch`
+- `CollectionPage` function (tab switcher + AnimatePresence)
+- `TAB_ORDER` and `slideVariants` constants
+- Imports from the three new component files
+
+Each extracted component is a named export, self-contained with its own hooks and local state.
+
+## 4. Docs Cleanup
+
+### PROJECT.md
+
+**File:** `.planning/PROJECT.md`
+
+Update Constraints section line:
+```
+- **Scope**: No auth, single user for v1
+```
+To:
+```
+- **Scope**: Single user with cookie/API key auth
+```
+
+## Commit Strategy
+
+Group into 3-4 commits by area:
+1. **Server hardening**: DB middleware, param validation, error handler, rate limiter, comment fix
+2. **Client resilience + refactor**: Error boundary, split collection route
+3. **Docs cleanup**: PROJECT.md update
+
+## Testing
+
+- All 183 existing tests must continue to pass
+- Rate limiter: manual verification (no automated test needed for in-memory rate limiting in a single-user app)
+- Error boundary: manual verification by triggering a render error
+- Param validation: existing route tests cover happy paths; invalid IDs are a new edge case but won't break existing tests

docs/superpowers/specs/2026-04-03-testing-improvements-design.md

@@ -0,0 +1,128 @@
+# Testing Improvements Design
+
+**Date:** 2026-04-03
+**Scope:** Unit tests for new server code + Playwright E2E test setup with seeded database
+
+## Part 1: Unit/Integration Tests (Bun test runner)
+
+### tests/lib/params.test.ts
+
+Tests for `parseId` helper in `src/server/lib/params.ts`:
+- Valid positive integers (1, 42, 999) return the number
+- Zero returns null
+- Negative numbers (-1, -100) return null
+- Decimals (1.5, 3.14) return null
+- Non-numeric strings ("abc", "", "hello") return null
+- NaN-producing values return null
+
+### tests/middleware/rateLimit.test.ts
+
+Tests for rate limiter in `src/server/middleware/rateLimit.ts`:
+- First request passes through (200)
+- 5 requests succeed, 6th returns 429
+- 429 response includes `Retry-After` header
+- Different IPs tracked independently
+- After window expires, requests succeed again
+
+Since the rate limiter uses a module-level `Map`, tests need to either:
+- Reset the store between tests (export a `resetStore` for testing), OR
+- Use unique paths/IPs per test to avoid interference
+
+Recommended: export a `_resetForTesting()` function from rateLimit.ts that clears the store. Only used in tests.
+
+### tests/routes/params.test.ts
+
+Route-level integration tests verifying 400 responses for invalid IDs:
+- `GET /api/items/abc` → 400
+- `GET /api/items/-1` → 400
+- `GET /api/items/0` → 400
+- `DELETE /api/categories/notanumber` → 400
+- `GET /api/threads/abc` → 400
+- `GET /api/setups/abc` → 400
+
+Uses existing test app pattern with in-memory DB.
+
+## Part 2: Playwright E2E Setup
+
+### Installation
+
+- `bun add -d @playwright/test`
+- `bunx playwright install chromium` (only Chromium needed)
+
+### Configuration: playwright.config.ts
+
+```ts
+export default defineConfig({
+  testDir: "./e2e",
+  webServer: {
+    command: "DATABASE_PATH=./e2e/test.db bun run dev:server",
+    port: 3000,
+    reuseExistingServer: !process.env.CI,
+  },
+  use: {
+    baseURL: "http://localhost:3000",
+  },
+  projects: [{ name: "chromium", use: { ...devices["Desktop Chrome"] } }],
+});
+```
+
+### Database Seeding: e2e/seed.ts
+
+Script that creates `e2e/test.db` with:
+- Run Drizzle migrations against the file
+- Seed data:
+  - 1 user (username: "admin", password: "password123")
+  - 3 categories: Shelter, Sleep System, Cook Kit
+  - 6 items across categories with realistic weights/prices
+  - 1 active thread with 3 candidates (with pros/cons, sort_order)
+  - 1 resolved thread
+  - 1 setup with 4 items (mixed classifications)
+  - Settings: weightUnit=g, currency=USD, onboardingComplete=true
+
+Run before E2E tests via `e2e/global-setup.ts` (Playwright globalSetup).
+
+### E2E Test Files
+
+**e2e/dashboard.spec.ts**
+- Dashboard page loads
+- Summary cards show item count, weight, cost
+- Navigation links to collection work
+
+**e2e/collection.spec.ts**
+- Gear tab renders items grouped by category
+- Search input filters items by name
+- Category filter dropdown works
+- Tab switching between gear/planning/setups
+
+**e2e/threads.spec.ts**
+- Thread detail page loads with candidates
+- Comparison view toggle works (shows table)
+- Rank badges visible on candidates
+
+**e2e/auth.spec.ts**
+- Login page renders
+- Login with valid credentials succeeds
+- Login with wrong password shows error
+- Rate limiting returns error after 5 attempts
+
+**e2e/error-boundary.spec.ts**
+- App doesn't white-screen on unknown routes
+- Navigating to a non-existent thread/setup shows appropriate error
+
+### Scripts
+
+Add to package.json:
+- `"test:e2e": "bunx playwright test"`
+- `"test:e2e:ui": "bunx playwright test --ui"` (for debugging)
+
+### Files to .gitignore
+
+- `e2e/test.db`
+- `test-results/`
+- `playwright-report/`
+
+## Commit Strategy
+
+1. Unit tests for parseId, rate limiter, route params
+2. Playwright setup (install, config, seed, global-setup)
+3. Playwright E2E test files

docs/superpowers/specs/2026-04-03-v1.4-collection-tools-design.md

@@ -0,0 +1,114 @@
+# v1.4 Collection Tools Design
+
+**Date:** 2026-04-03
+**Milestone:** v1.4 Collection Tools
+**Scope:** Setup impact preview, item quantity, CSV import/export, item duplication
+
+## Feature 1: Setup Impact Preview
+
+Already fully designed in `.planning/phases/13-setup-impact-preview/`. Two plans exist:
+- **13-01**: Pure `computeImpactDeltas` function + `useImpactDeltas` hook + uiStore state (TDD)
+- **13-02**: `SetupImpactSelector` + `ImpactDeltaBadge` components wired into thread detail
+
+Execute the existing plans as-is. No design changes needed.
+
+## Feature 2: Item Quantity
+
+### Schema
+
+Add `quantity INTEGER NOT NULL DEFAULT 1` to `items` table via Drizzle migration.
+
+```ts
+quantity: integer("quantity").notNull().default(1),
+```
+
+### Validation
+
+Add to `createItemSchema` in `src/shared/schemas.ts`:
+```ts
+quantity: z.number().int().positive().optional(),
+```
+
+Flows to `updateItemSchema` via `.partial()` automatically.
+
+### Service Layer
+
+No special business logic — quantity is a stored field.
+
+**Totals computation changes:**
+- `totals.service.ts`: `getCategoryTotals()` and `getGlobalTotals()` must multiply `weightGrams * quantity` and `priceCents * quantity` in their SQL SUM aggregations.
+- `setup.service.ts`: `getSetupWithItems()` and `getAllSetups()` — when computing setup totals, multiply item weight/price by the item's quantity.
+
+### UI
+
+- **ItemForm**: Number input for quantity (min=1), placed below price field. Defaults to 1.
+- **ItemCard**: Show "x2" badge next to item name when quantity > 1. No badge when quantity is 1.
+- **Totals**: Already computed server-side with the quantity multiplication. No client-side changes for totals.
+- **Setup weight/cost**: The item's quantity determines its weight/cost contribution when included in a setup (one `setup_items` row, but totals reflect quantity).
+
+### Thread Resolution
+
+When a thread is resolved and a candidate is copied to an item, the new item gets `quantity: 1` (default). No special handling needed.
+
+## Feature 3: CSV Import/Export
+
+### Export
+
+**Endpoint:** `GET /api/items/export`
+- Returns CSV with headers: `name,quantity,weightGrams,priceCents,category,notes,productUrl`
+- `Content-Type: text/csv`
+- `Content-Disposition: attachment; filename="gearbox-export.csv"`
+- Weight in grams, price in cents (raw values, no formatting)
+- Category column contains category name (not ID)
+
+**Service:** `exportItemsCsv(db)` returns a CSV string. Joins items with categories for name lookup.
+
+### Import
+
+**Endpoint:** `POST /api/items/import`
+- Accepts multipart form upload (CSV file)
+- Parses rows, validates required fields (name is required, others optional)
+- Category matching: looks up by name (case-insensitive). Creates new category if not found.
+- Quantity defaults to 1 if not present in CSV
+- Returns `{ imported: number, created_categories: string[], errors: string[] }`
+- Skips rows with errors, continues processing remaining rows
+
+**Service:** `importItemsCsv(db, csvContent: string)` parses and inserts items.
+
+### UI
+
+Settings page gets an "Import/Export" section:
+- "Export CSV" button — triggers download via `GET /api/items/export`
+- "Import CSV" file input — accepts .csv files, shows count of parsed rows, confirm button to upload
+- Success/error feedback after import completes
+
+## Feature 4: Item Duplication
+
+### API
+
+**Endpoint:** `POST /api/items/:id/duplicate`
+- Copies all fields from source item: name, weightGrams, priceCents, categoryId, notes, productUrl, imageFilename, imageSourceUrl, quantity
+- Appends " (copy)" to the name
+- New `createdAt`/`updatedAt` timestamps
+- Returns the new item
+
+**Service:** `duplicateItem(db, id)` — fetches source item, inserts copy, returns new item.
+
+### UI
+
+- Add "Duplicate" action to ItemCard (alongside existing edit/delete actions)
+- Duplicating opens the edit panel pre-filled with the new item so the user can rename or adjust
+
+## Phase Ordering
+
+1. **Item Quantity** — schema change first since CSV import/export and totals depend on it
+2. **Setup Impact Preview** — execute existing Phase 13 plans
+3. **Item Duplication** — small, self-contained
+4. **CSV Import/Export** — depends on quantity field existing in schema
+
+## Out of Scope
+
+- Quantity per setup (setup_items.quantity) — items table quantity is sufficient for v1.4
+- CSV export with formatted weights/prices — raw values are more portable
+- Image export/import via CSV — images are local files, not CSV-compatible
+- Bulk edit from CSV preview — import creates, doesn't update existing items

drizzle/0008_loving_colossus.sql

@@ -0,0 +1 @@
+ALTER TABLE `items` ADD `quantity` integer DEFAULT 1 NOT NULL;

drizzle/meta/0008_snapshot.json

@@ -0,0 +1,663 @@
+{
+  "version": "6",
+  "dialect": "sqlite",
+  "id": "ede9f482-7af0-42bc-9672-43f5fba289d0",
+  "prevId": "738e67c5-ebad-46c1-9261-6ab60ec4bdb1",
+  "tables": {
+    "api_keys": {
+      "name": "api_keys",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "integer",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": true
+        },
+        "name": {
+          "name": "name",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "key_hash": {
+          "name": "key_hash",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "key_prefix": {
+          "name": "key_prefix",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {},
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "categories": {
+      "name": "categories",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "integer",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": true
+        },
+        "name": {
+          "name": "name",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "icon": {
+          "name": "icon",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": "'package'"
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {
+        "categories_name_unique": {
+          "name": "categories_name_unique",
+          "columns": [
+            "name"
+          ],
+          "isUnique": true
+        }
+      },
+      "foreignKeys": {},
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "items": {
+      "name": "items",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "integer",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": true
+        },
+        "name": {
+          "name": "name",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "weight_grams": {
+          "name": "weight_grams",
+          "type": "real",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "price_cents": {
+          "name": "price_cents",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "category_id": {
+          "name": "category_id",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "notes": {
+          "name": "notes",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "product_url": {
+          "name": "product_url",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "image_filename": {
+          "name": "image_filename",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "image_source_url": {
+          "name": "image_source_url",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "quantity": {
+          "name": "quantity",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": 1
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "updated_at": {
+          "name": "updated_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {
+        "items_category_id_categories_id_fk": {
+          "name": "items_category_id_categories_id_fk",
+          "tableFrom": "items",
+          "tableTo": "categories",
+          "columnsFrom": [
+            "category_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "no action",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "sessions": {
+      "name": "sessions",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "user_id": {
+          "name": "user_id",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "expires_at": {
+          "name": "expires_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {
+        "sessions_user_id_users_id_fk": {
+          "name": "sessions_user_id_users_id_fk",
+          "tableFrom": "sessions",
+          "tableTo": "users",
+          "columnsFrom": [
+            "user_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "cascade",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "settings": {
+      "name": "settings",
+      "columns": {
+        "key": {
+          "name": "key",
+          "type": "text",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "value": {
+          "name": "value",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {},
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "setup_items": {
+      "name": "setup_items",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "integer",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": true
+        },
+        "setup_id": {
+          "name": "setup_id",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "item_id": {
+          "name": "item_id",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "classification": {
+          "name": "classification",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": "'base'"
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {
+        "setup_items_setup_id_setups_id_fk": {
+          "name": "setup_items_setup_id_setups_id_fk",
+          "tableFrom": "setup_items",
+          "tableTo": "setups",
+          "columnsFrom": [
+            "setup_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "cascade",
+          "onUpdate": "no action"
+        },
+        "setup_items_item_id_items_id_fk": {
+          "name": "setup_items_item_id_items_id_fk",
+          "tableFrom": "setup_items",
+          "tableTo": "items",
+          "columnsFrom": [
+            "item_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "cascade",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "setups": {
+      "name": "setups",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "integer",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": true
+        },
+        "name": {
+          "name": "name",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "updated_at": {
+          "name": "updated_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {},
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "thread_candidates": {
+      "name": "thread_candidates",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "integer",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": true
+        },
+        "thread_id": {
+          "name": "thread_id",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "name": {
+          "name": "name",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "weight_grams": {
+          "name": "weight_grams",
+          "type": "real",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "price_cents": {
+          "name": "price_cents",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "category_id": {
+          "name": "category_id",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "notes": {
+          "name": "notes",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "product_url": {
+          "name": "product_url",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "image_filename": {
+          "name": "image_filename",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "image_source_url": {
+          "name": "image_source_url",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "status": {
+          "name": "status",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": "'researching'"
+        },
+        "pros": {
+          "name": "pros",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "cons": {
+          "name": "cons",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "sort_order": {
+          "name": "sort_order",
+          "type": "real",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": 0
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "updated_at": {
+          "name": "updated_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {
+        "thread_candidates_thread_id_threads_id_fk": {
+          "name": "thread_candidates_thread_id_threads_id_fk",
+          "tableFrom": "thread_candidates",
+          "tableTo": "threads",
+          "columnsFrom": [
+            "thread_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "cascade",
+          "onUpdate": "no action"
+        },
+        "thread_candidates_category_id_categories_id_fk": {
+          "name": "thread_candidates_category_id_categories_id_fk",
+          "tableFrom": "thread_candidates",
+          "tableTo": "categories",
+          "columnsFrom": [
+            "category_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "no action",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "threads": {
+      "name": "threads",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "integer",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": true
+        },
+        "name": {
+          "name": "name",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "status": {
+          "name": "status",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false,
+          "default": "'active'"
+        },
+        "resolved_candidate_id": {
+          "name": "resolved_candidate_id",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": false,
+          "autoincrement": false
+        },
+        "category_id": {
+          "name": "category_id",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "updated_at": {
+          "name": "updated_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {},
+      "foreignKeys": {
+        "threads_category_id_categories_id_fk": {
+          "name": "threads_category_id_categories_id_fk",
+          "tableFrom": "threads",
+          "tableTo": "categories",
+          "columnsFrom": [
+            "category_id"
+          ],
+          "columnsTo": [
+            "id"
+          ],
+          "onDelete": "no action",
+          "onUpdate": "no action"
+        }
+      },
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    },
+    "users": {
+      "name": "users",
+      "columns": {
+        "id": {
+          "name": "id",
+          "type": "integer",
+          "primaryKey": true,
+          "notNull": true,
+          "autoincrement": true
+        },
+        "username": {
+          "name": "username",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "password_hash": {
+          "name": "password_hash",
+          "type": "text",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        },
+        "created_at": {
+          "name": "created_at",
+          "type": "integer",
+          "primaryKey": false,
+          "notNull": true,
+          "autoincrement": false
+        }
+      },
+      "indexes": {
+        "users_username_unique": {
+          "name": "users_username_unique",
+          "columns": [
+            "username"
+          ],
+          "isUnique": true
+        }
+      },
+      "foreignKeys": {},
+      "compositePrimaryKeys": {},
+      "uniqueConstraints": {},
+      "checkConstraints": {}
+    }
+  },
+  "views": {},
+  "enums": {},
+  "_meta": {
+    "schemas": {},
+    "tables": {},
+    "columns": {}
+  },
+  "internal": {
+    "indexes": {}
+  }
+}

drizzle/meta/_journal.json

@@ -57,6 +57,13 @@
       "when": 1775215076284,
       "tag": "0007_icy_prodigy",
       "breakpoints": true
+    },
+    {
+      "idx": 8,
+      "version": "6",
+      "when": 1775232090363,
+      "tag": "0008_loving_colossus",
+      "breakpoints": true
     }
   ]
 }

e2e/auth.spec.ts

@@ -0,0 +1,47 @@
+import { expect, test } from "@playwright/test";
+
+test.describe("Authentication", () => {
+	test("login page renders at /login", async ({ page }) => {
+		await page.goto("/login");
+		await page.waitForLoadState("networkidle");
+
+		// Should show the Sign In heading
+		await expect(page.getByRole("heading", { name: "Sign In" })).toBeVisible({
+			timeout: 5000,
+		});
+
+		// Should have username and password inputs
+		await expect(page.locator("#username")).toBeVisible({ timeout: 5000 });
+		await expect(page.locator("#password")).toBeVisible({ timeout: 5000 });
+	});
+
+	test("login with valid credentials succeeds and redirects away from /login", async ({
+		page,
+	}) => {
+		await page.goto("/login");
+		await page.waitForLoadState("networkidle");
+
+		await page.locator("#username").fill("admin");
+		await page.locator("#password").fill("password123");
+		await page.getByRole("button", { name: "Sign In" }).click();
+
+		// After successful login, should redirect to / (dashboard)
+		await page.waitForURL("/", { timeout: 5000 });
+		await expect(page).not.toHaveURL(/\/login/);
+		await expect(page.getByText("GearBox")).toBeVisible({ timeout: 5000 });
+	});
+
+	test("login with wrong password shows error", async ({ page }) => {
+		await page.goto("/login");
+		await page.waitForLoadState("networkidle");
+
+		await page.locator("#username").fill("admin");
+		await page.locator("#password").fill("wrongpassword");
+		await page.getByRole("button", { name: "Sign In" }).click();
+
+		// Should stay on the login page and show an error message
+		await expect(page).toHaveURL(/\/login/, { timeout: 5000 });
+		// The error paragraph should be visible (login.tsx renders <p className="text-sm text-red-600">{error}</p>)
+		await expect(page.locator(".text-red-600")).toBeVisible({ timeout: 5000 });
+	});
+});

e2e/collection.spec.ts

@@ -0,0 +1,89 @@
+import { expect, test } from "@playwright/test";
+
+test.describe("Collection page", () => {
+	test.beforeEach(async ({ page }) => {
+		await page.goto("/collection");
+		await page.waitForLoadState("networkidle");
+	});
+
+	test.describe("Gear tab", () => {
+		test("shows seeded items", async ({ page }) => {
+			await expect(page.getByText("Zpacks Duplex")).toBeVisible();
+			await expect(page.getByText("BRS-3000T Stove")).toBeVisible();
+		});
+
+		test("search filters items by name", async ({ page }) => {
+			const searchInput = page.getByPlaceholder("Search items...");
+			await searchInput.fill("Zpacks");
+			await expect(page.getByText("Zpacks Duplex")).toBeVisible();
+			// Other items should not be visible
+			await expect(page.getByText("BRS-3000T Stove")).not.toBeVisible();
+		});
+
+		test("clearing search restores all items", async ({ page }) => {
+			const searchInput = page.getByPlaceholder("Search items...");
+			await searchInput.fill("Zpacks");
+			await expect(page.getByText("BRS-3000T Stove")).not.toBeVisible();
+			// Clear the search
+			await searchInput.clear();
+			await expect(page.getByText("BRS-3000T Stove")).toBeVisible();
+		});
+
+		test("category filter dropdown opens and lists categories", async ({
+			page,
+		}) => {
+			const filterButton = page.getByRole("button", {
+				name: /all categories/i,
+			});
+			await filterButton.click();
+
+			// Dropdown list (ul) contains the category options
+			const dropdown = page.locator("ul");
+			await expect(
+				dropdown.getByRole("button", { name: "Shelter" }),
+			).toBeVisible();
+			await expect(
+				dropdown.getByRole("button", { name: "Cook Kit" }),
+			).toBeVisible();
+		});
+
+		test("category filter shows only items in selected category", async ({
+			page,
+		}) => {
+			// Open filter dropdown
+			const filterButton = page.getByRole("button", {
+				name: /all categories/i,
+			});
+			await filterButton.click();
+
+			// Select "Shelter" from the dropdown list
+			const dropdown = page.locator("ul");
+			await dropdown.getByRole("button", { name: "Shelter" }).click();
+
+			await expect(page.getByText("Zpacks Duplex")).toBeVisible();
+			// Items from other categories should not be visible
+			await expect(page.getByText("BRS-3000T Stove")).not.toBeVisible();
+		});
+	});
+
+	test.describe("Tab switching", () => {
+		test("navigates to planning tab", async ({ page }) => {
+			await page.goto("/collection?tab=planning");
+			await page.waitForLoadState("networkidle");
+			// Planning tab shows the active thread
+			await expect(page.getByText("New Backpack")).toBeVisible();
+		});
+
+		test("navigates to setups tab", async ({ page }) => {
+			await page.goto("/collection?tab=setups");
+			await page.waitForLoadState("networkidle");
+			// Setups tab shows the seeded setup
+			await expect(page.getByText("Weekend Overnighter")).toBeVisible();
+		});
+
+		test("gear tab is default and shows items", async ({ page }) => {
+			// Default tab (no ?tab param) shows gear
+			await expect(page.getByText("Zpacks Duplex")).toBeVisible();
+		});
+	});
+});

e2e/dashboard.spec.ts

@@ -0,0 +1,56 @@
+import { expect, test } from "@playwright/test";
+
+test.describe("Dashboard", () => {
+	test.beforeEach(async ({ page }) => {
+		await page.goto("/");
+		await page.waitForLoadState("networkidle");
+	});
+
+	test("shows GearBox heading", async ({ page }) => {
+		await expect(page.getByText("GearBox")).toBeVisible();
+	});
+
+	test("shows collection card with item count of 6", async ({ page }) => {
+		// The Collection card link contains "Items" label and value "6"
+		const collectionCard = page
+			.getByRole("link", { name: /collection/i })
+			.first();
+		await expect(collectionCard).toBeVisible();
+		await expect(collectionCard.getByText("6")).toBeVisible();
+	});
+
+	test("shows Collection, Planning, and Setups card headings", async ({
+		page,
+	}) => {
+		await expect(
+			page.getByRole("heading", { name: "Collection" }),
+		).toBeVisible();
+		await expect(page.getByRole("heading", { name: "Planning" })).toBeVisible();
+		await expect(page.getByRole("heading", { name: "Setups" })).toBeVisible();
+	});
+
+	test("Collection card links to /collection", async ({ page }) => {
+		const collectionLink = page
+			.getByRole("link", { name: /collection/i })
+			.first();
+		await collectionLink.click();
+		await page.waitForLoadState("networkidle");
+		await expect(page).toHaveURL(/\/collection/);
+	});
+
+	test("shows active thread count on Planning card", async ({ page }) => {
+		// The Planning card is a link containing "Active threads"
+		const planningCard = page.getByRole("link", { name: /planning/i });
+		await expect(planningCard.getByText("Active threads")).toBeVisible();
+		// Seed has 1 active thread
+		await expect(planningCard.getByText("1")).toBeVisible();
+	});
+
+	test("shows setup count on Setups card", async ({ page }) => {
+		// The Setups card has a heading "Setups"
+		await expect(page.getByRole("heading", { name: "Setups" })).toBeVisible();
+		// Seed has 1 setup
+		const setupsCard = page.getByRole("link", { name: /setups/i }).last();
+		await expect(setupsCard.getByText("1")).toBeVisible();
+	});
+});

e2e/error-handling.spec.ts

@@ -0,0 +1,59 @@
+import { expect, test } from "@playwright/test";
+
+test.describe("Error handling — non-existent routes", () => {
+	test("non-existent thread does not white-screen", async ({ page }) => {
+		await page.goto("/threads/99999");
+
+		// React Query retries failed requests (default 3 times with backoff) before
+		// setting isError=true. Wait for the page to leave loading state and show content.
+		// The thread detail page renders "Thread not found" + "Back to planning" link on error.
+		await expect(page.getByText("Back to planning")).toBeVisible({
+			timeout: 30000,
+		});
+		await expect(page.getByText("Thread not found")).toBeVisible({
+			timeout: 5000,
+		});
+	});
+
+	test("non-existent setup does not white-screen", async ({ page }) => {
+		await page.goto("/setups/99999");
+		await page.waitForLoadState("networkidle");
+
+		// Setup detail shows "Setup not found." when data is null (no retry — isLoading=false, data=undefined)
+		// The setup query resolves with undefined rather than throwing for missing items.
+		// Check that the page has content (not a blank screen).
+		const body = page.locator("body");
+		await expect(body).not.toBeEmpty();
+
+		// Navigation header should be visible (app did not crash)
+		await expect(page.getByText("GearBox")).toBeVisible({ timeout: 5000 });
+
+		// Wait for setup data to load; it will show "Setup not found." when done
+		await expect(page.getByText("Setup not found.")).toBeVisible({
+			timeout: 30000,
+		});
+	});
+
+	test("app recovers after bad route — dashboard loads fine", async ({
+		page,
+	}) => {
+		// Navigate to a non-existent thread first
+		await page.goto("/threads/99999");
+
+		// The page should render without crashing — wait for the error state
+		// (React Query retries before showing isError state, so use a long timeout)
+		await expect(page.getByText("Back to planning")).toBeVisible({
+			timeout: 30000,
+		});
+
+		// Now navigate to the dashboard
+		await page.goto("/");
+		await page.waitForLoadState("networkidle");
+
+		// Dashboard should load normally
+		await expect(page.getByText("GearBox")).toBeVisible({ timeout: 5000 });
+		await expect(page.getByRole("heading", { name: "Collection" })).toBeVisible(
+			{ timeout: 5000 },
+		);
+	});
+});

e2e/global-setup.ts

@@ -0,0 +1,10 @@
+import { seedTestDatabase } from "./seed";
+
+export default async function globalSetup() {
+	await seedTestDatabase();
+}
+
+// Allow direct invocation: bun run e2e/global-setup.ts
+if (import.meta.main) {
+	await globalSetup();
+}

e2e/seed.ts

@@ -0,0 +1,220 @@
+import { Database } from "bun:sqlite";
+import { unlink } from "node:fs/promises";
+import { drizzle } from "drizzle-orm/bun-sqlite";
+import { migrate } from "drizzle-orm/bun-sqlite/migrator";
+import * as schema from "../src/db/schema";
+
+const DB_PATH = "./e2e/test.db";
+
+export async function seedTestDatabase() {
+	// Remove old test DB if it exists
+	try {
+		await unlink(DB_PATH);
+	} catch {
+		// File doesn't exist, that's fine
+	}
+
+	const sqlite = new Database(DB_PATH);
+	sqlite.run("PRAGMA journal_mode = WAL");
+	sqlite.run("PRAGMA foreign_keys = ON");
+
+	const db = drizzle(sqlite, { schema });
+	migrate(db, { migrationsFolder: "./drizzle" });
+
+	// ── Categories ──
+	const [uncategorized] = db
+		.insert(schema.categories)
+		.values({ name: "Uncategorized", icon: "package" })
+		.returning()
+		.all();
+
+	const [shelter] = db
+		.insert(schema.categories)
+		.values({ name: "Shelter", icon: "tent" })
+		.returning()
+		.all();
+
+	const [sleep] = db
+		.insert(schema.categories)
+		.values({ name: "Sleep System", icon: "moon" })
+		.returning()
+		.all();
+
+	const [cook] = db
+		.insert(schema.categories)
+		.values({ name: "Cook Kit", icon: "flame" })
+		.returning()
+		.all();
+
+	// ── Items ──
+	const tent = db
+		.insert(schema.items)
+		.values({
+			name: "Zpacks Duplex",
+			weightGrams: 539,
+			priceCents: 67900,
+			categoryId: shelter.id,
+			notes: "DCF shelter, 2-person",
+		})
+		.returning()
+		.get();
+
+	db.insert(schema.items)
+		.values({
+			name: "Borah Gear Tarp",
+			weightGrams: 156,
+			priceCents: 11000,
+			categoryId: shelter.id,
+		})
+		.run();
+
+	const quilt = db
+		.insert(schema.items)
+		.values({
+			name: "Enlightened Equipment Enigma 20",
+			weightGrams: 595,
+			priceCents: 34000,
+			categoryId: sleep.id,
+			notes: "20F quilt",
+		})
+		.returning()
+		.get();
+
+	const pad = db
+		.insert(schema.items)
+		.values({
+			name: "Therm-a-Rest NeoAir XLite",
+			weightGrams: 354,
+			priceCents: 20999,
+			categoryId: sleep.id,
+		})
+		.returning()
+		.get();
+
+	const stove = db
+		.insert(schema.items)
+		.values({
+			name: "BRS-3000T Stove",
+			weightGrams: 25,
+			priceCents: 2000,
+			categoryId: cook.id,
+		})
+		.returning()
+		.get();
+
+	db.insert(schema.items)
+		.values({
+			name: "Toaks 750ml Pot",
+			weightGrams: 103,
+			priceCents: 3000,
+			categoryId: cook.id,
+		})
+		.run();
+
+	// ── Active Thread with 3 Candidates ──
+	const activeThread = db
+		.insert(schema.threads)
+		.values({
+			name: "New Backpack",
+			status: "active",
+			categoryId: uncategorized.id,
+		})
+		.returning()
+		.get();
+
+	db.insert(schema.threadCandidates)
+		.values({
+			threadId: activeThread.id,
+			name: "ULA Circuit",
+			weightGrams: 1077,
+			priceCents: 27500,
+			categoryId: uncategorized.id,
+			pros: "Great hip belt\nLarge capacity",
+			cons: "Heavier than competitors",
+			sortOrder: 1000,
+			status: "researching",
+		})
+		.run();
+
+	db.insert(schema.threadCandidates)
+		.values({
+			threadId: activeThread.id,
+			name: "Gossamer Gear Mariposa",
+			weightGrams: 737,
+			priceCents: 28500,
+			categoryId: uncategorized.id,
+			pros: "Very lightweight\nGood ventilation",
+			cons: "Smaller hip belt pockets",
+			sortOrder: 2000,
+			status: "researching",
+		})
+		.run();
+
+	db.insert(schema.threadCandidates)
+		.values({
+			threadId: activeThread.id,
+			name: "Granite Gear Crown2 38",
+			weightGrams: 850,
+			priceCents: 18000,
+			categoryId: uncategorized.id,
+			sortOrder: 3000,
+			status: "ordered",
+		})
+		.run();
+
+	// ── Resolved Thread ──
+	const resolvedThread = db
+		.insert(schema.threads)
+		.values({
+			name: "Camp Stove",
+			status: "resolved",
+			categoryId: cook.id,
+			resolvedCandidateId: 1,
+		})
+		.returning()
+		.get();
+
+	db.insert(schema.threadCandidates)
+		.values({
+			threadId: resolvedThread.id,
+			name: "BRS-3000T",
+			weightGrams: 25,
+			priceCents: 2000,
+			categoryId: cook.id,
+			sortOrder: 1000,
+			status: "arrived",
+		})
+		.run();
+
+	// ── Setup with Items ──
+	const setup = db
+		.insert(schema.setups)
+		.values({ name: "Weekend Overnighter" })
+		.returning()
+		.get();
+
+	db.insert(schema.setupItems)
+		.values([
+			{ setupId: setup.id, itemId: tent.id, classification: "base" },
+			{ setupId: setup.id, itemId: quilt.id, classification: "base" },
+			{ setupId: setup.id, itemId: pad.id, classification: "base" },
+			{ setupId: setup.id, itemId: stove.id, classification: "consumable" },
+		])
+		.run();
+
+	// ── User ──
+	const passwordHash = await Bun.password.hash("password123");
+	db.insert(schema.users).values({ username: "admin", passwordHash }).run();
+
+	// ── Settings ──
+	db.insert(schema.settings)
+		.values([
+			{ key: "weightUnit", value: "g" },
+			{ key: "currency", value: "USD" },
+			{ key: "onboardingComplete", value: "true" },
+		])
+		.run();
+
+	sqlite.close();
+	console.log("E2E test database seeded at", DB_PATH);
+}

e2e/start-test-server.sh

@@ -0,0 +1,4 @@
+#!/bin/sh
+# Seed the test database, then start the production server
+bun run e2e/global-setup.ts
+NODE_ENV=production DATABASE_PATH=./e2e/test.db bun run src/server/index.ts

e2e/threads.spec.ts

@@ -0,0 +1,113 @@
+import { expect, test } from "@playwright/test";
+
+test.describe("Thread detail page", () => {
+	test("loads with candidates visible", async ({ page }) => {
+		await page.goto("/collection?tab=planning");
+		await page.waitForLoadState("networkidle");
+
+		// Click the "New Backpack" thread card
+		await page.getByText("New Backpack").click();
+		await page.waitForLoadState("networkidle");
+
+		// Thread detail page should show the thread name
+		await expect(
+			page.getByRole("heading", { name: "New Backpack" }),
+		).toBeVisible({ timeout: 5000 });
+
+		// Candidates should be visible
+		await expect(page.getByText("ULA Circuit")).toBeVisible({ timeout: 5000 });
+		await expect(page.getByText("Gossamer Gear Mariposa")).toBeVisible({
+			timeout: 5000,
+		});
+		await expect(page.getByText("Granite Gear Crown2 38")).toBeVisible({
+			timeout: 5000,
+		});
+	});
+
+	test("rank badges are visible for top 3 candidates", async ({ page }) => {
+		await page.goto("/collection?tab=planning");
+		await page.waitForLoadState("networkidle");
+
+		await page.getByText("New Backpack").click();
+		await page.waitForLoadState("networkidle");
+
+		// Rank badges are medal icons — the component renders LucideIcon with name="medal"
+		// for ranks 1, 2, 3. We can verify via SVG elements or by checking the page has
+		// the expected number of medal icons (one per top candidate).
+		// The list view is default, which renders CandidateListItem with RankBadge.
+		// With 3 candidates all in top 3, all 3 get medal icons.
+		await expect(page.locator("text=ULA Circuit")).toBeVisible({
+			timeout: 5000,
+		});
+		await expect(page.locator("text=Gossamer Gear Mariposa")).toBeVisible({
+			timeout: 5000,
+		});
+		await expect(page.locator("text=Granite Gear Crown2 38")).toBeVisible({
+			timeout: 5000,
+		});
+
+		// Verify candidates are rendered (rank badges are SVG medals, not text)
+		// Check that at least the 3 candidates are present in the list
+		const candidateRows = page.locator(".bg-white.rounded-xl.border");
+		await expect(candidateRows).toHaveCount(3, { timeout: 5000 });
+	});
+
+	test("comparison view toggle works", async ({ page }) => {
+		await page.goto("/collection?tab=planning");
+		await page.waitForLoadState("networkidle");
+
+		await page.getByText("New Backpack").click();
+		await page.waitForLoadState("networkidle");
+
+		await expect(page.getByText("ULA Circuit")).toBeVisible({ timeout: 5000 });
+
+		// The compare button is a button with title="Compare view" (icon button with columns-3 icon)
+		const compareButton = page.getByRole("button", { name: "Compare view" });
+		await expect(compareButton).toBeVisible({ timeout: 5000 });
+		await compareButton.click();
+
+		// After clicking, a table should appear with Weight and Price row labels
+		await expect(page.locator("table")).toBeVisible({ timeout: 5000 });
+		// The comparison table renders row labels in sticky <td> cells (exact match to avoid
+		// matching candidate notes that contain the word "weight" or "price")
+		await expect(
+			page.getByRole("cell", { name: "Weight", exact: true }),
+		).toBeVisible({ timeout: 5000 });
+		await expect(
+			page.getByRole("cell", { name: "Price", exact: true }),
+		).toBeVisible({ timeout: 5000 });
+
+		// All 3 candidates should appear as table column headers (in <thead>)
+		await expect(page.locator("thead").getByText("ULA Circuit")).toBeVisible({
+			timeout: 5000,
+		});
+		await expect(
+			page.locator("thead").getByText("Gossamer Gear Mariposa"),
+		).toBeVisible({ timeout: 5000 });
+	});
+
+	test("resolved thread shows winner banner", async ({ page }) => {
+		await page.goto("/collection?tab=planning");
+		await page.waitForLoadState("networkidle");
+
+		// Click the "Resolved" tab pill button in the planning view
+		await page.getByRole("button", { name: "Resolved" }).click();
+		await page.waitForLoadState("networkidle");
+
+		// Camp Stove resolved thread should appear
+		await expect(page.getByText("Camp Stove")).toBeVisible({ timeout: 5000 });
+
+		// Click the Camp Stove thread card and wait for URL to change to thread detail
+		await page.getByText("Camp Stove").click();
+		await page.waitForURL(/\/threads\/\d+/, { timeout: 5000 });
+		await page.waitForLoadState("networkidle");
+
+		// Should show the resolved thread heading
+		await expect(page.getByRole("heading", { name: "Camp Stove" })).toBeVisible(
+			{ timeout: 5000 },
+		);
+
+		// The winner candidate (BRS-3000T) should be visible in the candidate list
+		await expect(page.getByText("BRS-3000T")).toBeVisible({ timeout: 5000 });
+	});
+});

package.json

@@ -10,11 +10,14 @@
 		"build": "vite build",
 		"db:generate": "bunx drizzle-kit generate",
 		"db:push": "bunx drizzle-kit push",
-		"test": "bun test",
+		"test": "bun test tests/",
+		"test:e2e": "bunx playwright test",
+		"test:e2e:ui": "bunx playwright test --ui",
 		"lint": "bunx @biomejs/biome check ."
 	},
 	"devDependencies": {
 		"@biomejs/biome": "^2.4.7",
+		"@playwright/test": "^1.59.1",
 		"@tanstack/react-query-devtools": "^5.91.3",
 		"@tanstack/react-router-devtools": "^1.166.7",
 		"@tanstack/router-plugin": "^1.166.9",

playwright.config.ts

@@ -0,0 +1,25 @@
+import { defineConfig, devices } from "@playwright/test";
+
+export default defineConfig({
+	testDir: "./e2e",
+	fullyParallel: false,
+	retries: 0,
+	workers: 1,
+	reporter: "list",
+	use: {
+		baseURL: "http://localhost:3000",
+		trace: "on-first-retry",
+	},
+	projects: [
+		{
+			name: "chromium",
+			use: { ...devices["Desktop Chrome"] },
+		},
+	],
+	webServer: {
+		command: "sh e2e/start-test-server.sh",
+		port: 3000,
+		reuseExistingServer: !process.env.CI,
+		timeout: 30000,
+	},
+});

src/client/components/CandidateCard.tsx

@@ -1,9 +1,9 @@
-import { useCurrency } from "../hooks/useCurrency";
-import { useWeightUnit } from "../hooks/useWeightUnit";
-import { formatPrice, formatWeight } from "../lib/formatters";
+import { useFormatters } from "../hooks/useFormatters";
+import type { CandidateDelta } from "../hooks/useImpactDeltas";
 import { LucideIcon } from "../lib/iconData";
 import { useUIStore } from "../stores/uiStore";
 import { RankBadge } from "./CandidateListItem";
+import { ImpactDeltaBadge } from "./ImpactDeltaBadge";
 import { StatusBadge } from "./StatusBadge";
 
 interface CandidateCardProps {
@@ -22,6 +22,7 @@ interface CandidateCardProps {
 	pros?: string | null;
 	cons?: string | null;
 	rank?: number;
+	delta?: CandidateDelta;
 }
 
 export function CandidateCard({
@@ -40,9 +41,9 @@ export function CandidateCard({
 	pros,
 	cons,
 	rank,
+	delta,
 }: CandidateCardProps) {
-	const unit = useWeightUnit();
-	const currency = useCurrency();
+	const { weight, price } = useFormatters();
 	const openCandidateEditPanel = useUIStore((s) => s.openCandidateEditPanel);
 	const openConfirmDeleteCandidate = useUIStore(
 		(s) => s.openConfirmDeleteCandidate,
@@ -165,14 +166,16 @@ export function CandidateCard({
 					{rank != null && <RankBadge rank={rank} />}
 					{weightGrams != null && (
 						<span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-blue-50 text-blue-400">
-							{formatWeight(weightGrams, unit)}
+							{weight(weightGrams)}
 						</span>
 					)}
+					<ImpactDeltaBadge delta={delta} type="weight" formatFn={weight} />
 					{priceCents != null && (
 						<span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-green-50 text-green-500">
-							{formatPrice(priceCents, currency)}
+							{price(priceCents)}
 						</span>
 					)}
+					<ImpactDeltaBadge delta={delta} type="price" formatFn={price} />
 					<span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-gray-50 text-gray-600">
 						<LucideIcon
 							name={categoryIcon}

src/client/components/CandidateListItem.tsx

@@ -1,9 +1,10 @@
-import { Reorder, useDragControls } from "framer-motion";
-import { useCurrency } from "../hooks/useCurrency";
-import { useWeightUnit } from "../hooks/useWeightUnit";
-import { formatPrice, formatWeight } from "../lib/formatters";
+import { Reorder } from "framer-motion";
+import { useRef } from "react";
+import { useFormatters } from "../hooks/useFormatters";
+import type { CandidateDelta } from "../hooks/useImpactDeltas";
 import { LucideIcon } from "../lib/iconData";
 import { useUIStore } from "../stores/uiStore";
+import { ImpactDeltaBadge } from "./ImpactDeltaBadge";
 import { StatusBadge } from "./StatusBadge";
 
 interface CandidateWithCategory {
@@ -30,6 +31,8 @@ interface CandidateListItemProps {
 	rank: number;
 	isActive: boolean;
 	onStatusChange: (status: "researching" | "ordered" | "arrived") => void;
+	delta?: CandidateDelta;
+	onDragEnd?: () => void;
 }
 
 const RANK_COLORS = ["#D4AF37", "#C0C0C0", "#CD7F32"]; // gold, silver, bronze
@@ -51,10 +54,11 @@ export function CandidateListItem({
 	rank,
 	isActive,
 	onStatusChange,
+	delta,
+	onDragEnd,
 }: CandidateListItemProps) {
-	const controls = useDragControls();
-	const unit = useWeightUnit();
-	const currency = useCurrency();
+	const isDragging = useRef(false);
+	const { weight, price } = useFormatters();
 	const openCandidateEditPanel = useUIStore((s) => s.openCandidateEditPanel);
 	const openConfirmDeleteCandidate = useUIStore(
 		(s) => s.openConfirmDeleteCandidate,
@@ -62,23 +66,16 @@ export function CandidateListItem({
 	const openResolveDialog = useUIStore((s) => s.openResolveDialog);
 	const openExternalLink = useUIStore((s) => s.openExternalLink);
 
-	return (
-		<Reorder.Item
-			value={candidate}
-			dragControls={controls}
-			dragListener={false}
-			className="flex items-center gap-3 bg-white rounded-xl border border-gray-100 p-3 hover:border-gray-200 hover:shadow-sm transition-all group cursor-default"
-		>
-			{/* Drag handle */}
+	const sharedClassName =
+		"flex items-center gap-3 bg-white rounded-xl border border-gray-100 p-3 hover:border-gray-200 hover:shadow-sm group cursor-default";
+
+	const innerContent = (
+		<>
+			{/* Drag handle indicator */}
 			{isActive && (
-				<button
-					type="button"
-					onPointerDown={(e) => controls.start(e)}
-					className="cursor-grab active:cursor-grabbing text-gray-300 hover:text-gray-500 touch-none shrink-0"
-					title="Drag to reorder"
-				>
+				<span className="text-gray-300 shrink-0">
 					<LucideIcon name="grip-vertical" size={16} />
-				</button>
+				</span>
 			)}
 
 			{/* Rank badge */}
@@ -104,7 +101,10 @@ export function CandidateListItem({
 			{/* Name + badges */}
 			<button
 				type="button"
-				onClick={() => openCandidateEditPanel(candidate.id)}
+				onClick={() => {
+					if (isDragging.current) return;
+					openCandidateEditPanel(candidate.id);
+				}}
 				className="flex-1 min-w-0 text-left"
 			>
 				<p className="text-sm font-semibold text-gray-900 truncate">
@@ -113,14 +113,16 @@ export function CandidateListItem({
 				<div className="flex flex-wrap gap-1.5 mt-1">
 					{candidate.weightGrams != null && (
 						<span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-blue-50 text-blue-400">
-							{formatWeight(candidate.weightGrams, unit)}
+							{weight(candidate.weightGrams)}
 						</span>
 					)}
+					<ImpactDeltaBadge delta={delta} type="weight" formatFn={weight} />
 					{candidate.priceCents != null && (
 						<span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-green-50 text-green-500">
-							{formatPrice(candidate.priceCents, currency)}
+							{price(candidate.priceCents)}
 						</span>
 					)}
+					<ImpactDeltaBadge delta={delta} type="price" formatFn={price} />
 					<span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-gray-50 text-gray-600">
 						<LucideIcon
 							name={candidate.categoryIcon}
@@ -206,6 +208,31 @@ export function CandidateListItem({
 					</svg>
 				</button>
 			</div>
-		</Reorder.Item>
+		</>
 	);
+
+	// Reorder.Item requires a Reorder.Group parent — only use it in active threads
+	if (isActive) {
+		return (
+			<Reorder.Item
+				value={candidate}
+				onDragStart={() => {
+					isDragging.current = true;
+				}}
+				onDragEnd={() => {
+					setTimeout(() => {
+						isDragging.current = false;
+					}, 0);
+					onDragEnd?.();
+				}}
+				whileDrag={{ cursor: "grabbing" }}
+				style={{ marginBottom: 8, cursor: "grab" }}
+				className={sharedClassName}
+			>
+				{innerContent}
+			</Reorder.Item>
+		);
+	}
+
+	return <div className={sharedClassName}>{innerContent}</div>;
 }

src/client/components/CategoryHeader.tsx

@@ -1,8 +1,6 @@
 import { useState } from "react";
 import { useDeleteCategory, useUpdateCategory } from "../hooks/useCategories";
-import { useCurrency } from "../hooks/useCurrency";
-import { useWeightUnit } from "../hooks/useWeightUnit";
-import { formatPrice, formatWeight } from "../lib/formatters";
+import { useFormatters } from "../hooks/useFormatters";
 import { LucideIcon } from "../lib/iconData";
 import { IconPicker } from "./IconPicker";
 
@@ -23,8 +21,7 @@ export function CategoryHeader({
 	totalCost,
 	itemCount,
 }: CategoryHeaderProps) {
-	const unit = useWeightUnit();
-	const currency = useCurrency();
+	const { weight, price } = useFormatters();
 	const [isEditing, setIsEditing] = useState(false);
 	const [editName, setEditName] = useState(name);
 	const [editIcon, setEditIcon] = useState(icon);
@@ -88,8 +85,8 @@ export function CategoryHeader({
 			<LucideIcon name={icon} size={22} className="text-gray-500" />
 			<h2 className="text-lg font-semibold text-gray-900">{name}</h2>
 			<span className="text-sm text-gray-400">
-				{itemCount} {itemCount === 1 ? "item" : "items"} ·{" "}
-				{formatWeight(totalWeight, unit)} · {formatPrice(totalCost, currency)}
+				{itemCount} {itemCount === 1 ? "item" : "items"} · {weight(totalWeight)}{" "}
+				· {price(totalCost)}
 			</span>
 			{!isUncategorized && (
 				<div className="ml-auto flex items-center gap-1 opacity-0 group-hover:opacity-100 transition-opacity">

src/client/components/CollectionView.tsx

@@ -0,0 +1,276 @@
+import { useMemo, useState } from "react";
+import { useCategories } from "../hooks/useCategories";
+import { useFormatters } from "../hooks/useFormatters";
+import { useItems } from "../hooks/useItems";
+import { useTotals } from "../hooks/useTotals";
+import { LucideIcon } from "../lib/iconData";
+import { useUIStore } from "../stores/uiStore";
+import { CategoryFilterDropdown } from "./CategoryFilterDropdown";
+import { CategoryHeader } from "./CategoryHeader";
+import { ItemCard } from "./ItemCard";
+
+export function CollectionView() {
+	const { data: items, isLoading: itemsLoading } = useItems();
+	const { data: totals } = useTotals();
+	const { data: categories } = useCategories();
+	const { weight, price } = useFormatters();
+	const openAddPanel = useUIStore((s) => s.openAddPanel);
+
+	const [searchText, setSearchText] = useState("");
+	const [categoryFilter, setCategoryFilter] = useState<number | null>(null);
+
+	const filteredItems = useMemo(() => {
+		if (!items) return [];
+		return items.filter((item) => {
+			const matchesSearch =
+				searchText === "" ||
+				item.name.toLowerCase().includes(searchText.toLowerCase());
+			const matchesCategory =
+				categoryFilter === null || item.categoryId === categoryFilter;
+			return matchesSearch && matchesCategory;
+		});
+	}, [items, searchText, categoryFilter]);
+
+	const hasActiveFilters = searchText !== "" || categoryFilter !== null;
+
+	if (itemsLoading) {
+		return (
+			<div className="animate-pulse space-y-6">
+				<div className="h-6 bg-gray-200 rounded w-48" />
+				<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
+					{[1, 2, 3].map((i) => (
+						<div key={i} className="h-40 bg-gray-200 rounded-xl" />
+					))}
+				</div>
+			</div>
+		);
+	}
+
+	if (!items || items.length === 0) {
+		return (
+			<div className="py-16 text-center">
+				<div className="max-w-md mx-auto">
+					<div className="mb-4">
+						<LucideIcon
+							name="backpack"
+							size={48}
+							className="text-gray-400 mx-auto"
+						/>
+					</div>
+					<h2 className="text-xl font-semibold text-gray-900 mb-2">
+						Your collection is empty
+					</h2>
+					<p className="text-sm text-gray-500 mb-6">
+						Start cataloging your gear by adding your first item. Track weight,
+						price, and organize by category.
+					</p>
+					<button
+						type="button"
+						onClick={openAddPanel}
+						className="inline-flex items-center gap-2 px-5 py-2.5 bg-gray-700 hover:bg-gray-800 text-white text-sm font-medium rounded-lg transition-colors"
+					>
+						<svg
+							aria-hidden="true"
+							className="w-4 h-4"
+							fill="none"
+							stroke="currentColor"
+							viewBox="0 0 24 24"
+						>
+							<path
+								strokeLinecap="round"
+								strokeLinejoin="round"
+								strokeWidth={2}
+								d="M12 4v16m8-8H4"
+							/>
+						</svg>
+						Add your first item
+					</button>
+				</div>
+			</div>
+		);
+	}
+
+	// Build category totals lookup
+	const categoryTotalsMap = new Map<
+		number,
+		{ totalWeight: number; totalCost: number; itemCount: number }
+	>();
+	if (totals?.categories) {
+		for (const ct of totals.categories) {
+			categoryTotalsMap.set(ct.categoryId, {
+				totalWeight: ct.totalWeight,
+				totalCost: ct.totalCost,
+				itemCount: ct.itemCount,
+			});
+		}
+	}
+
+	// Group filtered items by categoryId (used when no active filters)
+	const groupedItems = new Map<
+		number,
+		{
+			items: typeof filteredItems;
+			categoryName: string;
+			categoryIcon: string;
+		}
+	>();
+
+	for (const item of filteredItems) {
+		const group = groupedItems.get(item.categoryId);
+		if (group) {
+			group.items.push(item);
+		} else {
+			groupedItems.set(item.categoryId, {
+				items: [item],
+				categoryName: item.categoryName,
+				categoryIcon: item.categoryIcon,
+			});
+		}
+	}
+
+	return (
+		<>
+			{/* Collection stats card */}
+			{totals?.global && (
+				<div className="bg-white rounded-xl border border-gray-100 p-5 mb-6">
+					<div className="flex items-center gap-8">
+						<div className="flex flex-col items-center gap-1">
+							<LucideIcon name="layers" size={14} className="text-gray-400" />
+							<span className="text-xs text-gray-500">Items</span>
+							<span className="text-sm font-semibold text-gray-900">
+								{totals.global.itemCount}
+							</span>
+						</div>
+						<div className="flex flex-col items-center gap-1">
+							<LucideIcon name="weight" size={14} className="text-gray-400" />
+							<span className="text-xs text-gray-500">Total Weight</span>
+							<span className="text-sm font-semibold text-gray-900">
+								{weight(totals.global.totalWeight)}
+							</span>
+						</div>
+						<div className="flex flex-col items-center gap-1">
+							<LucideIcon
+								name="credit-card"
+								size={14}
+								className="text-gray-400"
+							/>
+							<span className="text-xs text-gray-500">Total Spent</span>
+							<span className="text-sm font-semibold text-gray-900">
+								{price(totals.global.totalCost)}
+							</span>
+						</div>
+					</div>
+				</div>
+			)}
+
+			{/* Search/filter toolbar */}
+			<div className="sticky top-0 z-10 bg-gray-50/95 backdrop-blur-sm border-b border-gray-100 -mx-4 px-4 py-3 sm:-mx-6 sm:px-6 lg:-mx-8 lg:px-8 mb-6">
+				<div className="flex gap-3 items-center">
+					<div className="relative flex-1">
+						<input
+							type="text"
+							placeholder="Search items..."
+							value={searchText}
+							onChange={(e) => setSearchText(e.target.value)}
+							className="w-full px-3 py-2 border border-gray-200 rounded-lg text-sm focus:outline-none focus:ring-2 focus:ring-gray-400 focus:border-transparent"
+						/>
+						{searchText && (
+							<button
+								type="button"
+								onClick={() => setSearchText("")}
+								className="absolute right-2 top-1/2 -translate-y-1/2 text-gray-400 hover:text-gray-600"
+							>
+								<svg
+									className="w-4 h-4"
+									fill="none"
+									stroke="currentColor"
+									viewBox="0 0 24 24"
+								>
+									<path
+										strokeLinecap="round"
+										strokeLinejoin="round"
+										strokeWidth={2}
+										d="M6 18L18 6M6 6l12 12"
+									/>
+								</svg>
+							</button>
+						)}
+					</div>
+					<CategoryFilterDropdown
+						value={categoryFilter}
+						onChange={setCategoryFilter}
+						categories={categories ?? []}
+					/>
+				</div>
+				{hasActiveFilters && (
+					<p className="text-xs text-gray-500 mt-2">
+						Showing {filteredItems.length} of {items.length} items
+					</p>
+				)}
+			</div>
+
+			{/* Filtered results */}
+			{hasActiveFilters ? (
+				filteredItems.length === 0 ? (
+					<div className="py-12 text-center">
+						<p className="text-sm text-gray-500">No items match your search</p>
+					</div>
+				) : (
+					<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
+						{filteredItems.map((item) => (
+							<ItemCard
+								key={item.id}
+								id={item.id}
+								name={item.name}
+								weightGrams={item.weightGrams}
+								priceCents={item.priceCents}
+								quantity={item.quantity}
+								categoryName={item.categoryName}
+								categoryIcon={item.categoryIcon}
+								imageFilename={item.imageFilename}
+								productUrl={item.productUrl}
+							/>
+						))}
+					</div>
+				)
+			) : (
+				Array.from(groupedItems.entries()).map(
+					([
+						categoryId,
+						{ items: categoryItems, categoryName, categoryIcon },
+					]) => {
+						const catTotals = categoryTotalsMap.get(categoryId);
+						return (
+							<div key={categoryId} className="mb-8">
+								<CategoryHeader
+									categoryId={categoryId}
+									name={categoryName}
+									icon={categoryIcon}
+									totalWeight={catTotals?.totalWeight ?? 0}
+									totalCost={catTotals?.totalCost ?? 0}
+									itemCount={catTotals?.itemCount ?? categoryItems.length}
+								/>
+								<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
+									{categoryItems.map((item) => (
+										<ItemCard
+											key={item.id}
+											id={item.id}
+											name={item.name}
+											weightGrams={item.weightGrams}
+											priceCents={item.priceCents}
+											quantity={item.quantity}
+											categoryName={categoryName}
+											categoryIcon={categoryIcon}
+											imageFilename={item.imageFilename}
+											productUrl={item.productUrl}
+										/>
+									))}
+								</div>
+							</div>
+						);
+					},
+				)
+			)}
+		</>
+	);
+}

src/client/components/ComparisonTable.tsx

@@ -1,10 +1,10 @@
 import { useMemo } from "react";
-import { useCurrency } from "../hooks/useCurrency";
-import { useWeightUnit } from "../hooks/useWeightUnit";
-import { formatPrice, formatWeight } from "../lib/formatters";
+import { useFormatters } from "../hooks/useFormatters";
+import type { CandidateDelta } from "../hooks/useImpactDeltas";
 import { LucideIcon } from "../lib/iconData";
 import { useUIStore } from "../stores/uiStore";
 import { RankBadge } from "./CandidateListItem";
+import { ImpactDeltaBadge } from "./ImpactDeltaBadge";
 
 interface CandidateWithCategory {
 	id: number;
@@ -28,6 +28,7 @@ interface CandidateWithCategory {
 interface ComparisonTableProps {
 	candidates: CandidateWithCategory[];
 	resolvedCandidateId: number | null;
+	deltas?: Record<number, CandidateDelta>;
 }
 
 const STATUS_LABELS: Record<"researching" | "ordered" | "arrived", string> = {
@@ -39,9 +40,9 @@ const STATUS_LABELS: Record<"researching" | "ordered" | "arrived", string> = {
 export function ComparisonTable({
 	candidates,
 	resolvedCandidateId,
+	deltas,
 }: ComparisonTableProps) {
-	const unit = useWeightUnit();
-	const currency = useCurrency();
+	const { weight, price } = useFormatters();
 	const openExternalLink = useUIStore((s) => s.openExternalLink);
 
 	const { bestWeightId, bestPriceId, weightDeltas, priceDeltas } =
@@ -62,8 +63,7 @@ export function ComparisonTable({
 						weightDeltas[c.id] = null;
 					} else {
 						const delta = c.weightGrams - minWeight;
-						weightDeltas[c.id] =
-							delta === 0 ? null : `+${formatWeight(delta, unit)}`;
+						weightDeltas[c.id] = delta === 0 ? null : `+${weight(delta)}`;
 					}
 				}
 			} else {
@@ -88,8 +88,7 @@ export function ComparisonTable({
 						priceDeltas[c.id] = null;
 					} else {
 						const delta = c.priceCents - minPrice;
-						priceDeltas[c.id] =
-							delta === 0 ? null : `+${formatPrice(delta, currency)}`;
+						priceDeltas[c.id] = delta === 0 ? null : `+${price(delta)}`;
 					}
 				}
 			} else {
@@ -99,7 +98,7 @@ export function ComparisonTable({
 			}
 
 			return { bestWeightId, bestPriceId, weightDeltas, priceDeltas };
-		}, [candidates, unit, currency]);
+		}, [candidates, weight, price]);
 
 	const ATTRIBUTE_ROWS: Array<{
 		key: string;
@@ -155,7 +154,7 @@ export function ComparisonTable({
 				return (
 					<div>
 						<span className="font-medium text-gray-900">
-							{formatWeight(c.weightGrams, unit)}
+							{weight(c.weightGrams)}
 						</span>
 						{!isBest && delta && (
 							<div className="text-xs text-gray-400">{delta}</div>
@@ -181,7 +180,7 @@ export function ComparisonTable({
 				return (
 					<div>
 						<span className="font-medium text-gray-900">
-							{formatPrice(c.priceCents, currency)}
+							{price(c.priceCents)}
 						</span>
 						{!isBest && delta && (
 							<div className="text-xs text-gray-400">{delta}</div>
@@ -268,6 +267,10 @@ export function ComparisonTable({
 		},
 	];
 
+	// Determine if impact rows should be shown
+	const firstDelta = deltas ? Object.values(deltas)[0] : undefined;
+	const showImpact = !!deltas && !!firstDelta && firstDelta.mode !== "none";
+
 	const tableMinWidth = Math.max(400, candidates.length * 180);
 
 	return (
@@ -329,6 +332,50 @@ export function ComparisonTable({
 							})}
 						</tr>
 					))}
+					{showImpact && (
+						<>
+							<tr className="border-b border-gray-50">
+								<td className="sticky left-0 z-10 bg-white px-4 py-3 text-xs font-medium text-gray-500 uppercase tracking-wide w-28">
+									Weight Impact
+								</td>
+								{candidates.map((candidate) => {
+									const isWinner = candidate.id === resolvedCandidateId;
+									return (
+										<td
+											key={candidate.id}
+											className={`px-4 py-3 min-w-[160px] ${isWinner ? "bg-amber-50/50" : ""}`}
+										>
+											<ImpactDeltaBadge
+												delta={deltas?.[candidate.id]}
+												type="weight"
+												formatFn={weight}
+											/>
+										</td>
+									);
+								})}
+							</tr>
+							<tr className="border-b border-gray-50">
+								<td className="sticky left-0 z-10 bg-white px-4 py-3 text-xs font-medium text-gray-500 uppercase tracking-wide w-28">
+									Price Impact
+								</td>
+								{candidates.map((candidate) => {
+									const isWinner = candidate.id === resolvedCandidateId;
+									return (
+										<td
+											key={candidate.id}
+											className={`px-4 py-3 min-w-[160px] ${isWinner ? "bg-amber-50/50" : ""}`}
+										>
+											<ImpactDeltaBadge
+												delta={deltas?.[candidate.id]}
+												type="price"
+												formatFn={price}
+											/>
+										</td>
+									);
+								})}
+							</tr>
+						</>
+					)}
 				</tbody>
 			</table>
 		</div>

src/client/components/ImpactDeltaBadge.tsx

@@ -0,0 +1,39 @@
+import type { CandidateDelta } from "../hooks/useImpactDeltas";
+
+interface ImpactDeltaBadgeProps {
+	delta: CandidateDelta | undefined;
+	type: "weight" | "price";
+	formatFn: (value: number) => string;
+}
+
+export function ImpactDeltaBadge({
+	delta,
+	type,
+	formatFn,
+}: ImpactDeltaBadgeProps) {
+	if (!delta || delta.mode === "none") return null;
+
+	const value = type === "weight" ? delta.weightDelta : delta.priceDelta;
+
+	if (value === null) {
+		return <span className="text-xs text-gray-400">—</span>;
+	}
+
+	if (value === 0) {
+		return <span className="text-xs text-gray-400">±0</span>;
+	}
+
+	if (value > 0) {
+		return (
+			<span className="text-xs text-green-600">
+				+{formatFn(value)}
+				{delta.mode === "add" && (
+					<span className="ml-0.5 text-green-500">(add)</span>
+				)}
+			</span>
+		);
+	}
+
+	// value < 0
+	return <span className="text-xs text-red-500">{formatFn(value)}</span>;
+}

src/client/components/ItemCard.tsx

@@ -1,6 +1,5 @@
-import { useCurrency } from "../hooks/useCurrency";
-import { useWeightUnit } from "../hooks/useWeightUnit";
-import { formatPrice, formatWeight } from "../lib/formatters";
+import { useFormatters } from "../hooks/useFormatters";
+import { useDuplicateItem } from "../hooks/useItems";
 import { LucideIcon } from "../lib/iconData";
 import { useUIStore } from "../stores/uiStore";
 import { ClassificationBadge } from "./ClassificationBadge";
@@ -10,6 +9,7 @@ interface ItemCardProps {
 	name: string;
 	weightGrams: number | null;
 	priceCents: number | null;
+	quantity?: number;
 	categoryName: string;
 	categoryIcon: string;
 	imageFilename: string | null;
@@ -24,6 +24,7 @@ export function ItemCard({
 	name,
 	weightGrams,
 	priceCents,
+	quantity,
 	categoryName,
 	categoryIcon,
 	imageFilename,
@@ -32,10 +33,10 @@ export function ItemCard({
 	classification,
 	onClassificationCycle,
 }: ItemCardProps) {
-	const unit = useWeightUnit();
-	const currency = useCurrency();
+	const { weight, price } = useFormatters();
 	const openEditPanel = useUIStore((s) => s.openEditPanel);
 	const openExternalLink = useUIStore((s) => s.openExternalLink);
+	const duplicateItem = useDuplicateItem();
 
 	return (
 		<button
@@ -43,6 +44,46 @@ export function ItemCard({
 			onClick={() => openEditPanel(id)}
 			className="relative w-full text-left bg-white rounded-xl border border-gray-100 hover:border-gray-200 hover:shadow-sm transition-all overflow-hidden group"
 		>
+			{!onRemove && (
+				<span
+					role="button"
+					tabIndex={0}
+					onClick={(e) => {
+						e.stopPropagation();
+						duplicateItem.mutate(id, {
+							onSuccess: (newItem) => {
+								openEditPanel(newItem.id);
+							},
+						});
+					}}
+					onKeyDown={(e) => {
+						if (e.key === "Enter" || e.key === " ") {
+							e.stopPropagation();
+							duplicateItem.mutate(id, {
+								onSuccess: (newItem) => {
+									openEditPanel(newItem.id);
+								},
+							});
+						}
+					}}
+					className={`absolute top-2 ${productUrl ? "right-10" : "right-2"} z-10 w-6 h-6 flex items-center justify-center rounded-full bg-gray-100/80 text-gray-400 hover:bg-blue-100 hover:text-blue-500 opacity-0 group-hover:opacity-100 transition-all cursor-pointer`}
+					title="Duplicate item"
+				>
+					<svg
+						className="w-3.5 h-3.5"
+						fill="none"
+						stroke="currentColor"
+						viewBox="0 0 24 24"
+					>
+						<path
+							strokeLinecap="round"
+							strokeLinejoin="round"
+							strokeWidth={2}
+							d="M8 16H6a2 2 0 01-2-2V6a2 2 0 012-2h8a2 2 0 012 2v2m-6 12h8a2 2 0 002-2v-8a2 2 0 00-2-2h-8a2 2 0 00-2 2v8a2 2 0 002 2z"
+						/>
+					</svg>
+				</span>
+			)}
 			{productUrl && (
 				<span
 					role="button"
@@ -125,18 +166,25 @@ export function ItemCard({
 				)}
 			</div>
 			<div className="p-4">
-				<h3 className="text-sm font-semibold text-gray-900 mb-2 truncate">
-					{name}
-				</h3>
+				<div className="flex items-center gap-1.5 mb-2">
+					<h3 className="text-sm font-semibold text-gray-900 truncate min-w-0">
+						{name}
+					</h3>
+					{quantity != null && quantity > 1 && (
+						<span className="shrink-0 inline-flex items-center px-1.5 py-0.5 rounded-full text-xs font-medium bg-gray-100 text-gray-600">
+							&times;{quantity}
+						</span>
+					)}
+				</div>
 				<div className="flex flex-wrap gap-1.5">
 					{weightGrams != null && (
 						<span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-blue-50 text-blue-400">
-							{formatWeight(weightGrams, unit)}
+							{weight(weightGrams)}
 						</span>
 					)}
 					{priceCents != null && (
 						<span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-green-50 text-green-500">
-							{formatPrice(priceCents, currency)}
+							{price(priceCents)}
 						</span>
 					)}
 					<span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-gray-50 text-gray-600">

src/client/components/ItemForm.tsx

@@ -13,6 +13,7 @@ interface FormData {
 	name: string;
 	weightGrams: string;
 	priceDollars: string;
+	quantity: number;
 	categoryId: number;
 	notes: string;
 	productUrl: string;
@@ -23,6 +24,7 @@ const INITIAL_FORM: FormData = {
 	name: "",
 	weightGrams: "",
 	priceDollars: "",
+	quantity: 1,
 	categoryId: 1,
 	notes: "",
 	productUrl: "",
@@ -49,6 +51,7 @@ export function ItemForm({ mode, itemId }: ItemFormProps) {
 					weightGrams: item.weightGrams != null ? String(item.weightGrams) : "",
 					priceDollars:
 						item.priceCents != null ? (item.priceCents / 100).toFixed(2) : "",
+					quantity: item.quantity ?? 1,
 					categoryId: item.categoryId,
 					notes: item.notes ?? "",
 					productUrl: item.productUrl ?? "",
@@ -98,6 +101,7 @@ export function ItemForm({ mode, itemId }: ItemFormProps) {
 			priceCents: form.priceDollars
 				? Math.round(Number(form.priceDollars) * 100)
 				: undefined,
+			quantity: form.quantity,
 			categoryId: form.categoryId,
 			notes: form.notes.trim() || undefined,
 			productUrl: form.productUrl.trim() || undefined,
@@ -202,6 +206,30 @@ export function ItemForm({ mode, itemId }: ItemFormProps) {
 				)}
 			</div>
 
+			{/* Quantity */}
+			<div>
+				<label
+					htmlFor="item-quantity"
+					className="block text-sm font-medium text-gray-700 mb-1"
+				>
+					Quantity
+				</label>
+				<input
+					id="item-quantity"
+					type="number"
+					min="1"
+					step="1"
+					value={form.quantity}
+					onChange={(e) =>
+						setForm((f) => ({
+							...f,
+							quantity: Math.max(1, Number(e.target.value) || 1),
+						}))
+					}
+					className="w-full px-3 py-2 border border-gray-200 rounded-lg text-sm focus:outline-none focus:ring-2 focus:ring-gray-400 focus:border-transparent"
+				/>
+			</div>
+
 			{/* Category */}
 			<div>
 				<label className="block text-sm font-medium text-gray-700 mb-1">

src/client/components/ItemPicker.tsx

@@ -1,9 +1,7 @@
 import { useEffect, useState } from "react";
-import { useCurrency } from "../hooks/useCurrency";
+import { useFormatters } from "../hooks/useFormatters";
 import { useItems } from "../hooks/useItems";
 import { useSyncSetupItems } from "../hooks/useSetups";
-import { useWeightUnit } from "../hooks/useWeightUnit";
-import { formatPrice, formatWeight } from "../lib/formatters";
 import { LucideIcon } from "../lib/iconData";
 import { SlideOutPanel } from "./SlideOutPanel";
 
@@ -22,8 +20,7 @@ export function ItemPicker({
 }: ItemPickerProps) {
 	const { data: items } = useItems();
 	const syncItems = useSyncSetupItems(setupId);
-	const unit = useWeightUnit();
-	const currency = useCurrency();
+	const { weight, price } = useFormatters();
 	const [selectedIds, setSelectedIds] = useState<Set<number>>(new Set());
 
 	// Reset selected IDs when panel opens
@@ -117,13 +114,11 @@ export function ItemPicker({
 													{item.name}
 												</span>
 												<span className="text-xs text-gray-400 shrink-0">
-													{item.weightGrams != null &&
-														formatWeight(item.weightGrams, unit)}
+													{item.weightGrams != null && weight(item.weightGrams)}
 													{item.weightGrams != null &&
 														item.priceCents != null &&
 														" · "}
-													{item.priceCents != null &&
-														formatPrice(item.priceCents, currency)}
+													{item.priceCents != null && price(item.priceCents)}
 												</span>
 											</label>
 										))}

src/client/components/PlanningView.tsx

@@ -0,0 +1,196 @@
+import { useState } from "react";
+import { useCategories } from "../hooks/useCategories";
+import { useThreads } from "../hooks/useThreads";
+import { useUIStore } from "../stores/uiStore";
+import { CategoryFilterDropdown } from "./CategoryFilterDropdown";
+import { CreateThreadModal } from "./CreateThreadModal";
+import { ThreadCard } from "./ThreadCard";
+
+export function PlanningView() {
+	const [activeTab, setActiveTab] = useState<"active" | "resolved">("active");
+	const [categoryFilter, setCategoryFilter] = useState<number | null>(null);
+
+	const openCreateThreadModal = useUIStore((s) => s.openCreateThreadModal);
+	const { data: categories } = useCategories();
+	const { data: threads, isLoading } = useThreads(activeTab === "resolved");
+
+	if (isLoading) {
+		return (
+			<div className="animate-pulse space-y-4">
+				{[1, 2].map((i) => (
+					<div key={i} className="h-24 bg-gray-200 rounded-xl" />
+				))}
+			</div>
+		);
+	}
+
+	// Filter threads by active tab and category
+	const filteredThreads = (threads ?? [])
+		.filter((t) => t.status === activeTab)
+		.filter((t) => (categoryFilter ? t.categoryId === categoryFilter : true));
+
+	// Determine if we should show the educational empty state
+	const isEmptyNoFilters =
+		filteredThreads.length === 0 &&
+		activeTab === "active" &&
+		categoryFilter === null &&
+		(!threads || threads.length === 0);
+
+	return (
+		<div>
+			{/* Header row */}
+			<div className="flex items-center justify-between mb-4">
+				<h2 className="text-lg font-semibold text-gray-900">
+					Planning Threads
+				</h2>
+				<button
+					type="button"
+					onClick={openCreateThreadModal}
+					className="inline-flex items-center gap-2 px-4 py-2 bg-gray-700 hover:bg-gray-800 text-white text-sm font-medium rounded-lg transition-colors"
+				>
+					<svg
+						aria-hidden="true"
+						className="w-4 h-4"
+						fill="none"
+						stroke="currentColor"
+						viewBox="0 0 24 24"
+					>
+						<path
+							strokeLinecap="round"
+							strokeLinejoin="round"
+							strokeWidth={2}
+							d="M12 4v16m8-8H4"
+						/>
+					</svg>
+					New Thread
+				</button>
+			</div>
+
+			{/* Filter row */}
+			<div className="flex items-center justify-between mb-6">
+				{/* Pill tabs */}
+				<div className="flex bg-gray-100 rounded-full p-0.5 gap-0.5">
+					<button
+						type="button"
+						onClick={() => setActiveTab("active")}
+						className={`px-4 py-1.5 text-sm font-medium rounded-full transition-colors ${
+							activeTab === "active"
+								? "bg-gray-700 text-white"
+								: "text-gray-600 hover:bg-gray-200"
+						}`}
+					>
+						Active
+					</button>
+					<button
+						type="button"
+						onClick={() => setActiveTab("resolved")}
+						className={`px-4 py-1.5 text-sm font-medium rounded-full transition-colors ${
+							activeTab === "resolved"
+								? "bg-gray-700 text-white"
+								: "text-gray-600 hover:bg-gray-200"
+						}`}
+					>
+						Resolved
+					</button>
+				</div>
+
+				{/* Category filter */}
+				<CategoryFilterDropdown
+					value={categoryFilter}
+					onChange={setCategoryFilter}
+					categories={categories ?? []}
+				/>
+			</div>
+
+			{/* Content: empty state or thread grid */}
+			{isEmptyNoFilters ? (
+				<div className="py-16">
+					<div className="max-w-lg mx-auto text-center">
+						<h2 className="text-xl font-semibold text-gray-900 mb-8">
+							Plan your next purchase
+						</h2>
+						<div className="space-y-6 text-left mb-10">
+							<div className="flex items-start gap-4">
+								<div className="flex items-center justify-center w-8 h-8 rounded-full bg-gray-200 text-gray-700 font-bold text-sm shrink-0">
+									1
+								</div>
+								<div>
+									<p className="font-medium text-gray-900">Create a thread</p>
+									<p className="text-sm text-gray-500">
+										Start a research thread for gear you're considering
+									</p>
+								</div>
+							</div>
+							<div className="flex items-start gap-4">
+								<div className="flex items-center justify-center w-8 h-8 rounded-full bg-gray-200 text-gray-700 font-bold text-sm shrink-0">
+									2
+								</div>
+								<div>
+									<p className="font-medium text-gray-900">Add candidates</p>
+									<p className="text-sm text-gray-500">
+										Add products you're comparing with prices and weights
+									</p>
+								</div>
+							</div>
+							<div className="flex items-start gap-4">
+								<div className="flex items-center justify-center w-8 h-8 rounded-full bg-gray-200 text-gray-700 font-bold text-sm shrink-0">
+									3
+								</div>
+								<div>
+									<p className="font-medium text-gray-900">Pick a winner</p>
+									<p className="text-sm text-gray-500">
+										Resolve the thread and the winner joins your collection
+									</p>
+								</div>
+							</div>
+						</div>
+						<button
+							type="button"
+							onClick={openCreateThreadModal}
+							className="inline-flex items-center gap-2 px-5 py-2.5 bg-gray-700 hover:bg-gray-800 text-white text-sm font-medium rounded-lg transition-colors"
+						>
+							<svg
+								aria-hidden="true"
+								className="w-4 h-4"
+								fill="none"
+								stroke="currentColor"
+								viewBox="0 0 24 24"
+							>
+								<path
+									strokeLinecap="round"
+									strokeLinejoin="round"
+									strokeWidth={2}
+									d="M12 4v16m8-8H4"
+								/>
+							</svg>
+							Create your first thread
+						</button>
+					</div>
+				</div>
+			) : filteredThreads.length === 0 ? (
+				<div className="py-12 text-center">
+					<p className="text-sm text-gray-500">No threads found</p>
+				</div>
+			) : (
+				<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
+					{filteredThreads.map((thread) => (
+						<ThreadCard
+							key={thread.id}
+							id={thread.id}
+							name={thread.name}
+							candidateCount={thread.candidateCount}
+							minPriceCents={thread.minPriceCents}
+							maxPriceCents={thread.maxPriceCents}
+							createdAt={thread.createdAt}
+							status={thread.status}
+							categoryName={thread.categoryName}
+							categoryIcon={thread.categoryIcon}
+						/>
+					))}
+				</div>
+			)}
+
+			<CreateThreadModal />
+		</div>
+	);
+}

src/client/components/SetupCard.tsx

@@ -1,7 +1,5 @@
 import { Link } from "@tanstack/react-router";
-import { useCurrency } from "../hooks/useCurrency";
-import { useWeightUnit } from "../hooks/useWeightUnit";
-import { formatPrice, formatWeight } from "../lib/formatters";
+import { useFormatters } from "../hooks/useFormatters";
 
 interface SetupCardProps {
 	id: number;
@@ -18,8 +16,7 @@ export function SetupCard({
 	totalWeight,
 	totalCost,
 }: SetupCardProps) {
-	const unit = useWeightUnit();
-	const currency = useCurrency();
+	const { weight, price } = useFormatters();
 	return (
 		<Link
 			to="/setups/$setupId"
@@ -34,10 +31,10 @@ export function SetupCard({
 			</div>
 			<div className="flex flex-wrap gap-1.5">
 				<span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-blue-50 text-blue-400">
-					{formatWeight(totalWeight, unit)}
+					{weight(totalWeight)}
 				</span>
 				<span className="inline-flex items-center px-2 py-0.5 rounded-full text-xs font-medium bg-green-50 text-green-500">
-					{formatPrice(totalCost, currency)}
+					{price(totalCost)}
 				</span>
 			</div>
 		</Link>

src/client/components/SetupImpactSelector.tsx

@@ -0,0 +1,34 @@
+import { useSetups } from "../hooks/useSetups";
+import { useUIStore } from "../stores/uiStore";
+
+interface SetupImpactSelectorProps {
+	threadStatus: "active" | "resolved";
+}
+
+export function SetupImpactSelector({
+	threadStatus,
+}: SetupImpactSelectorProps) {
+	const { data: setups } = useSetups();
+	const selectedSetupId = useUIStore((s) => s.selectedSetupId);
+	const setSelectedSetupId = useUIStore((s) => s.setSelectedSetupId);
+
+	if (threadStatus !== "active") return null;
+	if (!setups || setups.length === 0) return null;
+
+	return (
+		<select
+			value={selectedSetupId ?? ""}
+			onChange={(e) =>
+				setSelectedSetupId(e.target.value ? Number(e.target.value) : null)
+			}
+			className="border border-gray-200 rounded-lg text-sm px-3 py-1.5 text-gray-700 bg-white focus:outline-none focus:ring-2 focus:ring-gray-300"
+		>
+			<option value="">Compare with setup...</option>
+			{setups.map((setup) => (
+				<option key={setup.id} value={setup.id}>
+					{setup.name}
+				</option>
+			))}
+		</select>
+	);
+}

src/client/components/SetupsView.tsx

@@ -0,0 +1,112 @@
+import { useState } from "react";
+import { useCreateSetup, useSetups } from "../hooks/useSetups";
+import { SetupCard } from "./SetupCard";
+
+export function SetupsView() {
+	const [newSetupName, setNewSetupName] = useState("");
+	const { data: setups, isLoading } = useSetups();
+	const createSetup = useCreateSetup();
+
+	function handleCreateSetup(e: React.FormEvent) {
+		e.preventDefault();
+		const name = newSetupName.trim();
+		if (!name) return;
+		createSetup.mutate({ name }, { onSuccess: () => setNewSetupName("") });
+	}
+
+	return (
+		<div>
+			{/* Create setup form */}
+			<form onSubmit={handleCreateSetup} className="flex gap-2 mb-6">
+				<input
+					type="text"
+					value={newSetupName}
+					onChange={(e) => setNewSetupName(e.target.value)}
+					placeholder="New setup name..."
+					className="flex-1 px-3 py-2 border border-gray-200 rounded-lg text-sm focus:outline-none focus:ring-2 focus:ring-gray-400 focus:border-transparent"
+				/>
+				<button
+					type="submit"
+					disabled={!newSetupName.trim() || createSetup.isPending}
+					className="px-4 py-2 bg-gray-700 hover:bg-gray-800 disabled:opacity-50 text-white text-sm font-medium rounded-lg transition-colors"
+				>
+					{createSetup.isPending ? "Creating..." : "Create"}
+				</button>
+			</form>
+
+			{/* Loading skeleton */}
+			{isLoading && (
+				<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
+					{[1, 2].map((i) => (
+						<div
+							key={i}
+							className="h-24 bg-gray-200 rounded-xl animate-pulse"
+						/>
+					))}
+				</div>
+			)}
+
+			{/* Empty state */}
+			{!isLoading && (!setups || setups.length === 0) && (
+				<div className="py-16">
+					<div className="max-w-lg mx-auto text-center">
+						<h2 className="text-xl font-semibold text-gray-900 mb-8">
+							Build your perfect loadout
+						</h2>
+						<div className="space-y-6 text-left mb-10">
+							<div className="flex items-start gap-4">
+								<div className="flex items-center justify-center w-8 h-8 rounded-full bg-gray-200 text-gray-700 font-bold text-sm shrink-0">
+									1
+								</div>
+								<div>
+									<p className="font-medium text-gray-900">Create a setup</p>
+									<p className="text-sm text-gray-500">
+										Name your loadout for a specific trip or activity
+									</p>
+								</div>
+							</div>
+							<div className="flex items-start gap-4">
+								<div className="flex items-center justify-center w-8 h-8 rounded-full bg-gray-200 text-gray-700 font-bold text-sm shrink-0">
+									2
+								</div>
+								<div>
+									<p className="font-medium text-gray-900">Add items</p>
+									<p className="text-sm text-gray-500">
+										Pick gear from your collection to include in the setup
+									</p>
+								</div>
+							</div>
+							<div className="flex items-start gap-4">
+								<div className="flex items-center justify-center w-8 h-8 rounded-full bg-gray-200 text-gray-700 font-bold text-sm shrink-0">
+									3
+								</div>
+								<div>
+									<p className="font-medium text-gray-900">Track weight</p>
+									<p className="text-sm text-gray-500">
+										See weight breakdown and optimize your pack
+									</p>
+								</div>
+							</div>
+						</div>
+					</div>
+				</div>
+			)}
+
+			{/* Setup grid */}
+			{!isLoading && setups && setups.length > 0 && (
+				<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
+					{setups.map((setup) => (
+						<SetupCard
+							key={setup.id}
+							id={setup.id}
+							name={setup.name}
+							itemCount={setup.itemCount}
+							totalWeight={setup.totalWeight}
+							totalCost={setup.totalCost}
+						/>
+					))}
+				</div>
+			)}
+		</div>
+	);
+}

src/client/components/ThreadCard.tsx

@@ -1,6 +1,5 @@
 import { useNavigate } from "@tanstack/react-router";
-import { useCurrency } from "../hooks/useCurrency";
-import { formatPrice } from "../lib/formatters";
+import { useFormatters } from "../hooks/useFormatters";
 import { LucideIcon } from "../lib/iconData";
 
 interface ThreadCardProps {
@@ -20,16 +19,6 @@ function formatDate(iso: string): string {
 	return d.toLocaleDateString("en-US", { month: "short", day: "numeric" });
 }
 
-function formatPriceRange(
-	min: number | null,
-	max: number | null,
-	currency: Parameters<typeof formatPrice>[1],
-): string | null {
-	if (min == null && max == null) return null;
-	if (min === max) return formatPrice(min, currency);
-	return `${formatPrice(min, currency)} - ${formatPrice(max, currency)}`;
-}
-
 export function ThreadCard({
 	id,
 	name,
@@ -42,10 +31,19 @@ export function ThreadCard({
 	categoryIcon,
 }: ThreadCardProps) {
 	const navigate = useNavigate();
-	const currency = useCurrency();
+	const { price } = useFormatters();
+
+	function formatPriceRange(
+		min: number | null,
+		max: number | null,
+	): string | null {
+		if (min == null && max == null) return null;
+		if (min === max) return price(min);
+		return `${price(min)} - ${price(max)}`;
+	}
 
 	const isResolved = status === "resolved";
-	const priceRange = formatPriceRange(minPriceCents, maxPriceCents, currency);
+	const priceRange = formatPriceRange(minPriceCents, maxPriceCents);
 
 	return (
 		<button

src/client/components/TotalsBar.tsx

@@ -1,9 +1,9 @@
 import { Link } from "@tanstack/react-router";
 import { useAuth, useLogout } from "../hooks/useAuth";
+import { useFormatters } from "../hooks/useFormatters";
 import { useUpdateSetting } from "../hooks/useSettings";
 import { useTotals } from "../hooks/useTotals";
-import { useWeightUnit } from "../hooks/useWeightUnit";
-import { formatPrice, formatWeight, type WeightUnit } from "../lib/formatters";
+import type { WeightUnit } from "../lib/formatters";
 import { LucideIcon } from "../lib/iconData";
 
 const UNITS: WeightUnit[] = ["g", "oz", "lb", "kg"];
@@ -23,7 +23,7 @@ export function TotalsBar({
 	const { data: auth } = useAuth();
 	const logout = useLogout();
 	const isAuthenticated = !!auth?.user;
-	const unit = useWeightUnit();
+	const { weight, price, unit } = useFormatters();
 	const updateSetting = useUpdateSetting();
 
 	// When no stats provided, use global totals (backward compatible)
@@ -34,14 +34,14 @@ export function TotalsBar({
 					{ label: "items", value: String(data.global.itemCount) },
 					{
 						label: "total",
-						value: formatWeight(data.global.totalWeight, unit),
+						value: weight(data.global.totalWeight),
 					},
-					{ label: "spent", value: formatPrice(data.global.totalCost) },
+					{ label: "spent", value: price(data.global.totalCost) },
 				]
 			: [
 					{ label: "items", value: "0" },
-					{ label: "total", value: formatWeight(null, unit) },
-					{ label: "spent", value: formatPrice(null) },
+					{ label: "total", value: weight(null) },
+					{ label: "spent", value: price(null) },
 				]);
 
 	const titleContent = (

src/client/components/WeightSummaryCard.tsx

@@ -7,8 +7,8 @@ import {
 	ResponsiveContainer,
 	Tooltip,
 } from "recharts";
+import { useFormatters } from "../hooks/useFormatters";
 import type { SetupItemWithCategory } from "../hooks/useSetups";
-import { useWeightUnit } from "../hooks/useWeightUnit";
 import { formatWeight, type WeightUnit } from "../lib/formatters";
 import { LucideIcon } from "../lib/iconData";
 
@@ -55,9 +55,15 @@ function buildCategoryChartData(items: SetupItemWithCategory[]): ChartDatum[] {
 	const groups = new Map<string, number>();
 	for (const item of items) {
 		const current = groups.get(item.categoryName) ?? 0;
-		groups.set(item.categoryName, current + (item.weightGrams ?? 0));
+		groups.set(
+			item.categoryName,
+			current + (item.weightGrams ?? 0) * (item.quantity ?? 1),
+		);
 	}
-	const total = items.reduce((sum, i) => sum + (i.weightGrams ?? 0), 0);
+	const total = items.reduce(
+		(sum, i) => sum + (i.weightGrams ?? 0) * (i.quantity ?? 1),
+		0,
+	);
 	return Array.from(groups.entries())
 		.filter(([, weight]) => weight > 0)
 		.map(([name, weight]) => ({
@@ -76,7 +82,8 @@ function buildClassificationChartData(
 		consumable: 0,
 	};
 	for (const item of items) {
-		groups[item.classification] += item.weightGrams ?? 0;
+		groups[item.classification] +=
+			(item.weightGrams ?? 0) * (item.quantity ?? 1);
 	}
 	const total = Object.values(groups).reduce((a, b) => a + b, 0);
 	return Object.entries(groups)
@@ -143,22 +150,28 @@ function LegendRow({
 }
 
 export function WeightSummaryCard({ items }: WeightSummaryCardProps) {
-	const unit = useWeightUnit();
+	const { unit } = useFormatters();
 	const [viewMode, setViewMode] = useState<ViewMode>("category");
 
 	const baseWeight = items.reduce(
 		(sum, i) =>
-			i.classification === "base" ? sum + (i.weightGrams ?? 0) : sum,
+			i.classification === "base"
+				? sum + (i.weightGrams ?? 0) * (i.quantity ?? 1)
+				: sum,
 		0,
 	);
 	const wornWeight = items.reduce(
 		(sum, i) =>
-			i.classification === "worn" ? sum + (i.weightGrams ?? 0) : sum,
+			i.classification === "worn"
+				? sum + (i.weightGrams ?? 0) * (i.quantity ?? 1)
+				: sum,
 		0,
 	);
 	const consumableWeight = items.reduce(
 		(sum, i) =>
-			i.classification === "consumable" ? sum + (i.weightGrams ?? 0) : sum,
+			i.classification === "consumable"
+				? sum + (i.weightGrams ?? 0) * (i.quantity ?? 1)
+				: sum,
 		0,
 	);
 	const totalWeight = baseWeight + wornWeight + consumableWeight;

src/client/hooks/useFormatters.ts

@@ -0,0 +1,14 @@
+import { formatPrice, formatWeight } from "../lib/formatters";
+import { useCurrency } from "./useCurrency";
+import { useWeightUnit } from "./useWeightUnit";
+
+export function useFormatters() {
+	const unit = useWeightUnit();
+	const currency = useCurrency();
+	return {
+		weight: (grams: number | null) => formatWeight(grams, unit),
+		price: (cents: number | null) => formatPrice(cents, currency),
+		unit,
+		currency,
+	};
+}

src/client/hooks/useImpactDeltas.ts

@@ -0,0 +1,22 @@
+import { useMemo } from "react";
+import {
+	type CandidateDelta,
+	type CandidateInput,
+	computeImpactDeltas,
+	type DeltaMode,
+	type ImpactDeltas,
+	type SetupItemInput,
+} from "../lib/impactDeltas";
+
+export type { CandidateDelta, DeltaMode, ImpactDeltas };
+
+export function useImpactDeltas(
+	candidates: CandidateInput[],
+	setupItems: SetupItemInput[] | undefined,
+	threadCategoryId: number,
+): ImpactDeltas {
+	return useMemo(
+		() => computeImpactDeltas(candidates, setupItems, threadCategoryId),
+		[candidates, setupItems, threadCategoryId],
+	);
+}

src/client/hooks/useItems.ts

@@ -1,12 +1,35 @@
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import type { CreateItem } from "../../shared/types";
-import { apiDelete, apiGet, apiPost, apiPut } from "../lib/api";
+import {
+	ApiError,
+	apiDelete,
+	apiGet,
+	apiPost,
+	apiPut,
+	apiUpload,
+} from "../lib/api";
+
+interface Item {
+	id: number;
+	name: string;
+	weightGrams: number | null;
+	priceCents: number | null;
+	quantity: number;
+	categoryId: number;
+	notes: string | null;
+	productUrl: string | null;
+	imageFilename: string | null;
+	imageSourceUrl: string | null;
+	createdAt: string;
+	updatedAt: string;
+}
 
 interface ItemWithCategory {
 	id: number;
 	name: string;
 	weightGrams: number | null;
 	priceCents: number | null;
+	quantity: number;
 	categoryId: number;
 	notes: string | null;
 	productUrl: string | null;
@@ -29,6 +52,8 @@ export function useItem(id: number | null) {
 		queryKey: ["items", id],
 		queryFn: () => apiGet<ItemWithCategory>(`/api/items/${id}`),
 		enabled: id != null,
+		retry: (count, error) =>
+			error instanceof ApiError && error.status === 404 ? false : count < 3,
 	});
 }
 
@@ -69,3 +94,38 @@ export function useDeleteItem() {
 		},
 	});
 }
+
+export function useDuplicateItem() {
+	const queryClient = useQueryClient();
+	return useMutation({
+		mutationFn: (id: number) => apiPost<Item>(`/api/items/${id}/duplicate`, {}),
+		onSuccess: () => {
+			queryClient.invalidateQueries({ queryKey: ["items"] });
+			queryClient.invalidateQueries({ queryKey: ["totals"] });
+		},
+	});
+}
+
+export function useExportItems() {
+	return function exportItems() {
+		window.location.href = "/api/items/export";
+	};
+}
+
+interface ImportResult {
+	imported: number;
+	createdCategories: string[];
+	errors: string[];
+}
+
+export function useImportItems() {
+	const queryClient = useQueryClient();
+	return useMutation({
+		mutationFn: (file: File) =>
+			apiUpload<ImportResult>("/api/items/import", file),
+		onSuccess: () => {
+			queryClient.invalidateQueries({ queryKey: ["items"] });
+			queryClient.invalidateQueries({ queryKey: ["totals"] });
+		},
+	});
+}

src/client/hooks/useSetups.ts

@@ -1,5 +1,12 @@
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
-import { apiDelete, apiGet, apiPatch, apiPost, apiPut } from "../lib/api";
+import {
+	ApiError,
+	apiDelete,
+	apiGet,
+	apiPatch,
+	apiPost,
+	apiPut,
+} from "../lib/api";
 
 interface SetupListItem {
 	id: number;
@@ -16,6 +23,7 @@ interface SetupItemWithCategory {
 	name: string;
 	weightGrams: number | null;
 	priceCents: number | null;
+	quantity: number;
 	categoryId: number;
 	notes: string | null;
 	productUrl: string | null;
@@ -49,6 +57,8 @@ export function useSetup(setupId: number | null) {
 		queryKey: ["setups", setupId],
 		queryFn: () => apiGet<SetupWithItems>(`/api/setups/${setupId}`),
 		enabled: setupId != null,
+		retry: (count, error) =>
+			error instanceof ApiError && error.status === 404 ? false : count < 3,
 	});
 }
 

src/client/hooks/useThreads.ts

@@ -1,5 +1,5 @@
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
-import { apiDelete, apiGet, apiPost, apiPut } from "../lib/api";
+import { ApiError, apiDelete, apiGet, apiPost, apiPut } from "../lib/api";
 
 interface ThreadListItem {
 	id: number;
@@ -40,6 +40,7 @@ interface ThreadWithCandidates {
 	name: string;
 	status: "active" | "resolved";
 	resolvedCandidateId: number | null;
+	categoryId: number;
 	createdAt: string;
 	updatedAt: string;
 	candidates: CandidateWithCategory[];
@@ -60,6 +61,8 @@ export function useThread(threadId: number | null) {
 		queryKey: ["threads", threadId],
 		queryFn: () => apiGet<ThreadWithCandidates>(`/api/threads/${threadId}`),
 		enabled: threadId != null,
+		retry: (count, error) =>
+			error instanceof ApiError && error.status === 404 ? false : count < 3,
 	});
 }
 

src/client/lib/api.ts

@@ -1,4 +1,4 @@
-class ApiError extends Error {
+export class ApiError extends Error {
 	constructor(
 		message: string,
 		public status: number,

src/client/lib/impactDeltas.ts

@@ -0,0 +1,69 @@
+export interface CandidateInput {
+	id: number;
+	weightGrams: number | null;
+	priceCents: number | null;
+}
+
+export interface SetupItemInput {
+	categoryId: number;
+	weightGrams: number | null;
+	priceCents: number | null;
+	name: string;
+}
+
+export type DeltaMode = "replace" | "add" | "none";
+
+export interface CandidateDelta {
+	candidateId: number;
+	mode: DeltaMode;
+	weightDelta: number | null;
+	priceDelta: number | null;
+	replacedItemName: string | null;
+}
+
+export interface ImpactDeltas {
+	mode: DeltaMode;
+	deltas: Record<number, CandidateDelta>;
+}
+
+export function computeImpactDeltas(
+	candidates: CandidateInput[],
+	setupItems: SetupItemInput[] | undefined,
+	threadCategoryId: number,
+): ImpactDeltas {
+	if (!setupItems) return { mode: "none", deltas: {} };
+
+	const replacedItem =
+		setupItems.find((item) => item.categoryId === threadCategoryId) ?? null;
+	const mode: DeltaMode = replacedItem ? "replace" : "add";
+	const deltas: Record<number, CandidateDelta> = {};
+
+	for (const candidate of candidates) {
+		let weightDelta: number | null = null;
+		let priceDelta: number | null = null;
+
+		if (candidate.weightGrams != null) {
+			weightDelta =
+				replacedItem?.weightGrams != null
+					? candidate.weightGrams - replacedItem.weightGrams
+					: candidate.weightGrams;
+		}
+
+		if (candidate.priceCents != null) {
+			priceDelta =
+				replacedItem?.priceCents != null
+					? candidate.priceCents - replacedItem.priceCents
+					: candidate.priceCents;
+		}
+
+		deltas[candidate.id] = {
+			candidateId: candidate.id,
+			mode,
+			weightDelta,
+			priceDelta,
+			replacedItemName: replacedItem?.name ?? null,
+		};
+	}
+
+	return { mode, deltas };
+}

src/client/routes/__root.tsx

@@ -1,8 +1,10 @@
 import {
 	createRootRoute,
+	type ErrorComponentProps,
 	Outlet,
 	useMatchRoute,
 	useNavigate,
+	useRouter,
 } from "@tanstack/react-router";
 import { useState } from "react";
 import "../app.css";
@@ -21,8 +23,53 @@ import { useUIStore } from "../stores/uiStore";
 
 export const Route = createRootRoute({
 	component: RootLayout,
+	errorComponent: RootErrorBoundary,
 });
 
+function RootErrorBoundary({ error, reset }: ErrorComponentProps) {
+	const router = useRouter();
+
+	return (
+		<div className="min-h-screen bg-gray-50 flex items-center justify-center">
+			<div className="max-w-md mx-auto text-center px-4">
+				<div className="w-12 h-12 bg-red-100 rounded-full flex items-center justify-center mx-auto mb-4">
+					<svg
+						className="w-6 h-6 text-red-600"
+						fill="none"
+						stroke="currentColor"
+						viewBox="0 0 24 24"
+					>
+						<path
+							strokeLinecap="round"
+							strokeLinejoin="round"
+							strokeWidth={2}
+							d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-2.5L13.732 4c-.77-.833-1.964-.833-2.732 0L4.082 16.5c-.77.833.192 2.5 1.732 2.5z"
+						/>
+					</svg>
+				</div>
+				<h1 className="text-xl font-semibold text-gray-900 mb-2">
+					Something went wrong
+				</h1>
+				<p className="text-sm text-gray-500 mb-6">
+					{error instanceof Error
+						? error.message
+						: "An unexpected error occurred"}
+				</p>
+				<button
+					type="button"
+					onClick={() => {
+						reset();
+						router.invalidate();
+					}}
+					className="px-5 py-2.5 bg-gray-700 hover:bg-gray-800 text-white text-sm font-medium rounded-lg transition-colors"
+				>
+					Try again
+				</button>
+			</div>
+		</div>
+	);
+}
+
 function RootLayout() {
 	const navigate = useNavigate();
 	const { data: auth } = useAuth();

src/client/routes/collection/index.tsx

@@ -1,23 +1,10 @@
-import { createFileRoute } from "@tanstack/react-router";
+import { createFileRoute, Link } from "@tanstack/react-router";
 import { AnimatePresence, motion } from "framer-motion";
-import { useMemo, useRef, useState } from "react";
+import { useRef } from "react";
 import { z } from "zod";
-import { CategoryFilterDropdown } from "../../components/CategoryFilterDropdown";
-import { CategoryHeader } from "../../components/CategoryHeader";
-import { CreateThreadModal } from "../../components/CreateThreadModal";
-import { ItemCard } from "../../components/ItemCard";
-import { SetupCard } from "../../components/SetupCard";
-import { ThreadCard } from "../../components/ThreadCard";
-import { useCategories } from "../../hooks/useCategories";
-import { useCurrency } from "../../hooks/useCurrency";
-import { useItems } from "../../hooks/useItems";
-import { useCreateSetup, useSetups } from "../../hooks/useSetups";
-import { useThreads } from "../../hooks/useThreads";
-import { useTotals } from "../../hooks/useTotals";
-import { useWeightUnit } from "../../hooks/useWeightUnit";
-import { formatPrice, formatWeight } from "../../lib/formatters";
-import { LucideIcon } from "../../lib/iconData";
-import { useUIStore } from "../../stores/uiStore";
+import { CollectionView } from "../../components/CollectionView";
+import { PlanningView } from "../../components/PlanningView";
+import { SetupsView } from "../../components/SetupsView";
 
 const searchSchema = z.object({
 	tab: z.enum(["gear", "planning", "setups"]).catch("gear"),
@@ -29,6 +16,11 @@ export const Route = createFileRoute("/collection/")({
 });
 
 const TAB_ORDER = ["gear", "planning", "setups"] as const;
+const TAB_LABELS: Record<(typeof TAB_ORDER)[number], string> = {
+	gear: "Gear",
+	planning: "Planning",
+	setups: "Setups",
+};
 
 const slideVariants = {
 	enter: (dir: number) => ({ x: `${dir * 15}%`, opacity: 0 }),
@@ -46,6 +38,26 @@ function CollectionPage() {
 
 	return (
 		<div className="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8 py-6 overflow-x-hidden">
+			{/* Tab navigation */}
+			<div className="flex justify-center mb-6">
+				<div className="flex bg-gray-100 rounded-full p-0.5 gap-0.5">
+					{TAB_ORDER.map((t) => (
+						<Link
+							key={t}
+							to="/collection"
+							search={{ tab: t }}
+							className={`px-4 py-1.5 text-sm font-medium rounded-full transition-colors ${
+								tab === t
+									? "bg-gray-700 text-white"
+									: "text-gray-600 hover:bg-gray-200"
+							}`}
+						>
+							{TAB_LABELS[t]}
+						</Link>
+					))}
+				</div>
+			</div>
+
 			<AnimatePresence mode="wait" initial={false} custom={direction}>
 				<motion.div
 					key={tab}
@@ -68,566 +80,3 @@ function CollectionPage() {
 		</div>
 	);
 }
-
-function CollectionView() {
-	const { data: items, isLoading: itemsLoading } = useItems();
-	const { data: totals } = useTotals();
-	const { data: categories } = useCategories();
-	const unit = useWeightUnit();
-	const currency = useCurrency();
-	const openAddPanel = useUIStore((s) => s.openAddPanel);
-
-	const [searchText, setSearchText] = useState("");
-	const [categoryFilter, setCategoryFilter] = useState<number | null>(null);
-
-	const filteredItems = useMemo(() => {
-		if (!items) return [];
-		return items.filter((item) => {
-			const matchesSearch =
-				searchText === "" ||
-				item.name.toLowerCase().includes(searchText.toLowerCase());
-			const matchesCategory =
-				categoryFilter === null || item.categoryId === categoryFilter;
-			return matchesSearch && matchesCategory;
-		});
-	}, [items, searchText, categoryFilter]);
-
-	const hasActiveFilters = searchText !== "" || categoryFilter !== null;
-
-	if (itemsLoading) {
-		return (
-			<div className="animate-pulse space-y-6">
-				<div className="h-6 bg-gray-200 rounded w-48" />
-				<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
-					{[1, 2, 3].map((i) => (
-						<div key={i} className="h-40 bg-gray-200 rounded-xl" />
-					))}
-				</div>
-			</div>
-		);
-	}
-
-	if (!items || items.length === 0) {
-		return (
-			<div className="py-16 text-center">
-				<div className="max-w-md mx-auto">
-					<div className="mb-4">
-						<LucideIcon
-							name="backpack"
-							size={48}
-							className="text-gray-400 mx-auto"
-						/>
-					</div>
-					<h2 className="text-xl font-semibold text-gray-900 mb-2">
-						Your collection is empty
-					</h2>
-					<p className="text-sm text-gray-500 mb-6">
-						Start cataloging your gear by adding your first item. Track weight,
-						price, and organize by category.
-					</p>
-					<button
-						type="button"
-						onClick={openAddPanel}
-						className="inline-flex items-center gap-2 px-5 py-2.5 bg-gray-700 hover:bg-gray-800 text-white text-sm font-medium rounded-lg transition-colors"
-					>
-						<svg
-							aria-hidden="true"
-							className="w-4 h-4"
-							fill="none"
-							stroke="currentColor"
-							viewBox="0 0 24 24"
-						>
-							<path
-								strokeLinecap="round"
-								strokeLinejoin="round"
-								strokeWidth={2}
-								d="M12 4v16m8-8H4"
-							/>
-						</svg>
-						Add your first item
-					</button>
-				</div>
-			</div>
-		);
-	}
-
-	// Build category totals lookup
-	const categoryTotalsMap = new Map<
-		number,
-		{ totalWeight: number; totalCost: number; itemCount: number }
-	>();
-	if (totals?.categories) {
-		for (const ct of totals.categories) {
-			categoryTotalsMap.set(ct.categoryId, {
-				totalWeight: ct.totalWeight,
-				totalCost: ct.totalCost,
-				itemCount: ct.itemCount,
-			});
-		}
-	}
-
-	// Group filtered items by categoryId (used when no active filters)
-	const groupedItems = new Map<
-		number,
-		{
-			items: typeof filteredItems;
-			categoryName: string;
-			categoryIcon: string;
-		}
-	>();
-
-	for (const item of filteredItems) {
-		const group = groupedItems.get(item.categoryId);
-		if (group) {
-			group.items.push(item);
-		} else {
-			groupedItems.set(item.categoryId, {
-				items: [item],
-				categoryName: item.categoryName,
-				categoryIcon: item.categoryIcon,
-			});
-		}
-	}
-
-	return (
-		<>
-			{/* Collection stats card */}
-			{totals?.global && (
-				<div className="bg-white rounded-xl border border-gray-100 p-5 mb-6">
-					<div className="flex items-center gap-8">
-						<div className="flex flex-col items-center gap-1">
-							<LucideIcon name="layers" size={14} className="text-gray-400" />
-							<span className="text-xs text-gray-500">Items</span>
-							<span className="text-sm font-semibold text-gray-900">
-								{totals.global.itemCount}
-							</span>
-						</div>
-						<div className="flex flex-col items-center gap-1">
-							<LucideIcon name="weight" size={14} className="text-gray-400" />
-							<span className="text-xs text-gray-500">Total Weight</span>
-							<span className="text-sm font-semibold text-gray-900">
-								{formatWeight(totals.global.totalWeight, unit)}
-							</span>
-						</div>
-						<div className="flex flex-col items-center gap-1">
-							<LucideIcon
-								name="credit-card"
-								size={14}
-								className="text-gray-400"
-							/>
-							<span className="text-xs text-gray-500">Total Spent</span>
-							<span className="text-sm font-semibold text-gray-900">
-								{formatPrice(totals.global.totalCost, currency)}
-							</span>
-						</div>
-					</div>
-				</div>
-			)}
-
-			{/* Search/filter toolbar */}
-			<div className="sticky top-0 z-10 bg-gray-50/95 backdrop-blur-sm border-b border-gray-100 -mx-4 px-4 py-3 sm:-mx-6 sm:px-6 lg:-mx-8 lg:px-8 mb-6">
-				<div className="flex gap-3 items-center">
-					<div className="relative flex-1">
-						<input
-							type="text"
-							placeholder="Search items..."
-							value={searchText}
-							onChange={(e) => setSearchText(e.target.value)}
-							className="w-full px-3 py-2 border border-gray-200 rounded-lg text-sm focus:outline-none focus:ring-2 focus:ring-gray-400 focus:border-transparent"
-						/>
-						{searchText && (
-							<button
-								type="button"
-								onClick={() => setSearchText("")}
-								className="absolute right-2 top-1/2 -translate-y-1/2 text-gray-400 hover:text-gray-600"
-							>
-								<svg
-									className="w-4 h-4"
-									fill="none"
-									stroke="currentColor"
-									viewBox="0 0 24 24"
-								>
-									<path
-										strokeLinecap="round"
-										strokeLinejoin="round"
-										strokeWidth={2}
-										d="M6 18L18 6M6 6l12 12"
-									/>
-								</svg>
-							</button>
-						)}
-					</div>
-					<CategoryFilterDropdown
-						value={categoryFilter}
-						onChange={setCategoryFilter}
-						categories={categories ?? []}
-					/>
-				</div>
-				{hasActiveFilters && (
-					<p className="text-xs text-gray-500 mt-2">
-						Showing {filteredItems.length} of {items.length} items
-					</p>
-				)}
-			</div>
-
-			{/* Filtered results */}
-			{hasActiveFilters ? (
-				filteredItems.length === 0 ? (
-					<div className="py-12 text-center">
-						<p className="text-sm text-gray-500">No items match your search</p>
-					</div>
-				) : (
-					<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
-						{filteredItems.map((item) => (
-							<ItemCard
-								key={item.id}
-								id={item.id}
-								name={item.name}
-								weightGrams={item.weightGrams}
-								priceCents={item.priceCents}
-								categoryName={item.categoryName}
-								categoryIcon={item.categoryIcon}
-								imageFilename={item.imageFilename}
-								productUrl={item.productUrl}
-							/>
-						))}
-					</div>
-				)
-			) : (
-				Array.from(groupedItems.entries()).map(
-					([
-						categoryId,
-						{ items: categoryItems, categoryName, categoryIcon },
-					]) => {
-						const catTotals = categoryTotalsMap.get(categoryId);
-						return (
-							<div key={categoryId} className="mb-8">
-								<CategoryHeader
-									categoryId={categoryId}
-									name={categoryName}
-									icon={categoryIcon}
-									totalWeight={catTotals?.totalWeight ?? 0}
-									totalCost={catTotals?.totalCost ?? 0}
-									itemCount={catTotals?.itemCount ?? categoryItems.length}
-								/>
-								<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
-									{categoryItems.map((item) => (
-										<ItemCard
-											key={item.id}
-											id={item.id}
-											name={item.name}
-											weightGrams={item.weightGrams}
-											priceCents={item.priceCents}
-											categoryName={categoryName}
-											categoryIcon={categoryIcon}
-											imageFilename={item.imageFilename}
-											productUrl={item.productUrl}
-										/>
-									))}
-								</div>
-							</div>
-						);
-					},
-				)
-			)}
-		</>
-	);
-}
-
-function PlanningView() {
-	const [activeTab, setActiveTab] = useState<"active" | "resolved">("active");
-	const [categoryFilter, setCategoryFilter] = useState<number | null>(null);
-
-	const openCreateThreadModal = useUIStore((s) => s.openCreateThreadModal);
-	const { data: categories } = useCategories();
-	const { data: threads, isLoading } = useThreads(activeTab === "resolved");
-
-	if (isLoading) {
-		return (
-			<div className="animate-pulse space-y-4">
-				{[1, 2].map((i) => (
-					<div key={i} className="h-24 bg-gray-200 rounded-xl" />
-				))}
-			</div>
-		);
-	}
-
-	// Filter threads by active tab and category
-	const filteredThreads = (threads ?? [])
-		.filter((t) => t.status === activeTab)
-		.filter((t) => (categoryFilter ? t.categoryId === categoryFilter : true));
-
-	// Determine if we should show the educational empty state
-	const isEmptyNoFilters =
-		filteredThreads.length === 0 &&
-		activeTab === "active" &&
-		categoryFilter === null &&
-		(!threads || threads.length === 0);
-
-	return (
-		<div>
-			{/* Header row */}
-			<div className="flex items-center justify-between mb-4">
-				<h2 className="text-lg font-semibold text-gray-900">
-					Planning Threads
-				</h2>
-				<button
-					type="button"
-					onClick={openCreateThreadModal}
-					className="inline-flex items-center gap-2 px-4 py-2 bg-gray-700 hover:bg-gray-800 text-white text-sm font-medium rounded-lg transition-colors"
-				>
-					<svg
-						aria-hidden="true"
-						className="w-4 h-4"
-						fill="none"
-						stroke="currentColor"
-						viewBox="0 0 24 24"
-					>
-						<path
-							strokeLinecap="round"
-							strokeLinejoin="round"
-							strokeWidth={2}
-							d="M12 4v16m8-8H4"
-						/>
-					</svg>
-					New Thread
-				</button>
-			</div>
-
-			{/* Filter row */}
-			<div className="flex items-center justify-between mb-6">
-				{/* Pill tabs */}
-				<div className="flex bg-gray-100 rounded-full p-0.5 gap-0.5">
-					<button
-						type="button"
-						onClick={() => setActiveTab("active")}
-						className={`px-4 py-1.5 text-sm font-medium rounded-full transition-colors ${
-							activeTab === "active"
-								? "bg-gray-700 text-white"
-								: "text-gray-600 hover:bg-gray-200"
-						}`}
-					>
-						Active
-					</button>
-					<button
-						type="button"
-						onClick={() => setActiveTab("resolved")}
-						className={`px-4 py-1.5 text-sm font-medium rounded-full transition-colors ${
-							activeTab === "resolved"
-								? "bg-gray-700 text-white"
-								: "text-gray-600 hover:bg-gray-200"
-						}`}
-					>
-						Resolved
-					</button>
-				</div>
-
-				{/* Category filter */}
-				<CategoryFilterDropdown
-					value={categoryFilter}
-					onChange={setCategoryFilter}
-					categories={categories ?? []}
-				/>
-			</div>
-
-			{/* Content: empty state or thread grid */}
-			{isEmptyNoFilters ? (
-				<div className="py-16">
-					<div className="max-w-lg mx-auto text-center">
-						<h2 className="text-xl font-semibold text-gray-900 mb-8">
-							Plan your next purchase
-						</h2>
-						<div className="space-y-6 text-left mb-10">
-							<div className="flex items-start gap-4">
-								<div className="flex items-center justify-center w-8 h-8 rounded-full bg-gray-200 text-gray-700 font-bold text-sm shrink-0">
-									1
-								</div>
-								<div>
-									<p className="font-medium text-gray-900">Create a thread</p>
-									<p className="text-sm text-gray-500">
-										Start a research thread for gear you're considering
-									</p>
-								</div>
-							</div>
-							<div className="flex items-start gap-4">
-								<div className="flex items-center justify-center w-8 h-8 rounded-full bg-gray-200 text-gray-700 font-bold text-sm shrink-0">
-									2
-								</div>
-								<div>
-									<p className="font-medium text-gray-900">Add candidates</p>
-									<p className="text-sm text-gray-500">
-										Add products you're comparing with prices and weights
-									</p>
-								</div>
-							</div>
-							<div className="flex items-start gap-4">
-								<div className="flex items-center justify-center w-8 h-8 rounded-full bg-gray-200 text-gray-700 font-bold text-sm shrink-0">
-									3
-								</div>
-								<div>
-									<p className="font-medium text-gray-900">Pick a winner</p>
-									<p className="text-sm text-gray-500">
-										Resolve the thread and the winner joins your collection
-									</p>
-								</div>
-							</div>
-						</div>
-						<button
-							type="button"
-							onClick={openCreateThreadModal}
-							className="inline-flex items-center gap-2 px-5 py-2.5 bg-gray-700 hover:bg-gray-800 text-white text-sm font-medium rounded-lg transition-colors"
-						>
-							<svg
-								aria-hidden="true"
-								className="w-4 h-4"
-								fill="none"
-								stroke="currentColor"
-								viewBox="0 0 24 24"
-							>
-								<path
-									strokeLinecap="round"
-									strokeLinejoin="round"
-									strokeWidth={2}
-									d="M12 4v16m8-8H4"
-								/>
-							</svg>
-							Create your first thread
-						</button>
-					</div>
-				</div>
-			) : filteredThreads.length === 0 ? (
-				<div className="py-12 text-center">
-					<p className="text-sm text-gray-500">No threads found</p>
-				</div>
-			) : (
-				<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
-					{filteredThreads.map((thread) => (
-						<ThreadCard
-							key={thread.id}
-							id={thread.id}
-							name={thread.name}
-							candidateCount={thread.candidateCount}
-							minPriceCents={thread.minPriceCents}
-							maxPriceCents={thread.maxPriceCents}
-							createdAt={thread.createdAt}
-							status={thread.status}
-							categoryName={thread.categoryName}
-							categoryIcon={thread.categoryIcon}
-						/>
-					))}
-				</div>
-			)}
-
-			<CreateThreadModal />
-		</div>
-	);
-}
-
-function SetupsView() {
-	const [newSetupName, setNewSetupName] = useState("");
-	const { data: setups, isLoading } = useSetups();
-	const createSetup = useCreateSetup();
-
-	function handleCreateSetup(e: React.FormEvent) {
-		e.preventDefault();
-		const name = newSetupName.trim();
-		if (!name) return;
-		createSetup.mutate({ name }, { onSuccess: () => setNewSetupName("") });
-	}
-
-	return (
-		<div>
-			{/* Create setup form */}
-			<form onSubmit={handleCreateSetup} className="flex gap-2 mb-6">
-				<input
-					type="text"
-					value={newSetupName}
-					onChange={(e) => setNewSetupName(e.target.value)}
-					placeholder="New setup name..."
-					className="flex-1 px-3 py-2 border border-gray-200 rounded-lg text-sm focus:outline-none focus:ring-2 focus:ring-gray-400 focus:border-transparent"
-				/>
-				<button
-					type="submit"
-					disabled={!newSetupName.trim() || createSetup.isPending}
-					className="px-4 py-2 bg-gray-700 hover:bg-gray-800 disabled:opacity-50 text-white text-sm font-medium rounded-lg transition-colors"
-				>
-					{createSetup.isPending ? "Creating..." : "Create"}
-				</button>
-			</form>
-
-			{/* Loading skeleton */}
-			{isLoading && (
-				<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
-					{[1, 2].map((i) => (
-						<div
-							key={i}
-							className="h-24 bg-gray-200 rounded-xl animate-pulse"
-						/>
-					))}
-				</div>
-			)}
-
-			{/* Empty state */}
-			{!isLoading && (!setups || setups.length === 0) && (
-				<div className="py-16">
-					<div className="max-w-lg mx-auto text-center">
-						<h2 className="text-xl font-semibold text-gray-900 mb-8">
-							Build your perfect loadout
-						</h2>
-						<div className="space-y-6 text-left mb-10">
-							<div className="flex items-start gap-4">
-								<div className="flex items-center justify-center w-8 h-8 rounded-full bg-gray-200 text-gray-700 font-bold text-sm shrink-0">
-									1
-								</div>
-								<div>
-									<p className="font-medium text-gray-900">Create a setup</p>
-									<p className="text-sm text-gray-500">
-										Name your loadout for a specific trip or activity
-									</p>
-								</div>
-							</div>
-							<div className="flex items-start gap-4">
-								<div className="flex items-center justify-center w-8 h-8 rounded-full bg-gray-200 text-gray-700 font-bold text-sm shrink-0">
-									2
-								</div>
-								<div>
-									<p className="font-medium text-gray-900">Add items</p>
-									<p className="text-sm text-gray-500">
-										Pick gear from your collection to include in the setup
-									</p>
-								</div>
-							</div>
-							<div className="flex items-start gap-4">
-								<div className="flex items-center justify-center w-8 h-8 rounded-full bg-gray-200 text-gray-700 font-bold text-sm shrink-0">
-									3
-								</div>
-								<div>
-									<p className="font-medium text-gray-900">Track weight</p>
-									<p className="text-sm text-gray-500">
-										See weight breakdown and optimize your pack
-									</p>
-								</div>
-							</div>
-						</div>
-					</div>
-				</div>
-			)}
-
-			{/* Setup grid */}
-			{!isLoading && setups && setups.length > 0 && (
-				<div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
-					{setups.map((setup) => (
-						<SetupCard
-							key={setup.id}
-							id={setup.id}
-							name={setup.name}
-							itemCount={setup.itemCount}
-							totalWeight={setup.totalWeight}
-							totalCost={setup.totalCost}
-						/>
-					))}
-				</div>
-			)}
-		</div>
-	);
-}

src/client/routes/index.tsx

@@ -1,11 +1,9 @@
 import { createFileRoute } from "@tanstack/react-router";
 import { DashboardCard } from "../components/DashboardCard";
-import { useCurrency } from "../hooks/useCurrency";
+import { useFormatters } from "../hooks/useFormatters";
 import { useSetups } from "../hooks/useSetups";
 import { useThreads } from "../hooks/useThreads";
 import { useTotals } from "../hooks/useTotals";
-import { useWeightUnit } from "../hooks/useWeightUnit";
-import { formatPrice, formatWeight } from "../lib/formatters";
 
 export const Route = createFileRoute("/")({
 	component: DashboardPage,
@@ -15,8 +13,7 @@ function DashboardPage() {
 	const { data: totals } = useTotals();
 	const { data: threads } = useThreads(false);
 	const { data: setups } = useSetups();
-	const unit = useWeightUnit();
-	const currency = useCurrency();
+	const { weight, price } = useFormatters();
 
 	const global = totals?.global;
 	const activeThreadCount = threads?.length ?? 0;
@@ -33,11 +30,11 @@ function DashboardPage() {
 						{ label: "Items", value: String(global?.itemCount ?? 0) },
 						{
 							label: "Weight",
-							value: formatWeight(global?.totalWeight ?? null, unit),
+							value: weight(global?.totalWeight ?? null),
 						},
 						{
 							label: "Cost",
-							value: formatPrice(global?.totalCost ?? null, currency),
+							value: price(global?.totalCost ?? null),
 						},
 					]}
 					emptyText="Get started"

src/client/routes/settings.tsx

@@ -1,5 +1,5 @@
 import { createFileRoute, Link } from "@tanstack/react-router";
-import { useState } from "react";
+import { useRef, useState } from "react";
 import {
 	useApiKeys,
 	useAuth,
@@ -8,6 +8,7 @@ import {
 	useDeleteApiKey,
 } from "../hooks/useAuth";
 import { useCurrency } from "../hooks/useCurrency";
+import { useExportItems, useImportItems } from "../hooks/useItems";
 import { useUpdateSetting } from "../hooks/useSettings";
 import { useWeightUnit } from "../hooks/useWeightUnit";
 import type { Currency, WeightUnit } from "../lib/formatters";
@@ -172,6 +173,95 @@ function ApiKeySection() {
 	);
 }
 
+function ImportExportSection() {
+	const exportItems = useExportItems();
+	const importItems = useImportItems();
+	const fileInputRef = useRef<HTMLInputElement>(null);
+	const [importResult, setImportResult] = useState<{
+		imported: number;
+		createdCategories: string[];
+		errors: string[];
+	} | null>(null);
+
+	async function handleFileChange(e: React.ChangeEvent<HTMLInputElement>) {
+		const file = e.target.files?.[0];
+		if (!file) return;
+		setImportResult(null);
+		try {
+			const result = await importItems.mutateAsync(file);
+			setImportResult(result);
+		} catch (err) {
+			setImportResult({
+				imported: 0,
+				createdCategories: [],
+				errors: [(err as Error).message],
+			});
+		}
+		// Reset so the same file can be imported again if needed
+		if (fileInputRef.current) fileInputRef.current.value = "";
+	}
+
+	return (
+		<div className="space-y-3">
+			<h3 className="text-sm font-medium text-gray-900">Import / Export</h3>
+			<p className="text-xs text-gray-500">
+				Export your gear collection as a CSV file, or import items from a CSV.
+			</p>
+
+			<div className="flex flex-wrap gap-2">
+				<button
+					type="button"
+					onClick={exportItems}
+					className="px-4 py-2 text-sm font-medium text-white bg-gray-700 hover:bg-gray-800 rounded-lg transition-colors"
+				>
+					Export CSV
+				</button>
+
+				<label className="px-4 py-2 text-sm font-medium text-gray-700 bg-white border border-gray-200 hover:bg-gray-50 rounded-lg transition-colors cursor-pointer">
+					{importItems.isPending ? "Importing..." : "Import CSV"}
+					<input
+						ref={fileInputRef}
+						type="file"
+						accept=".csv"
+						className="hidden"
+						disabled={importItems.isPending}
+						onChange={handleFileChange}
+					/>
+				</label>
+			</div>
+
+			{importResult && (
+				<div
+					className={`rounded-lg p-3 text-xs space-y-1 ${
+						importResult.errors.length > 0 && importResult.imported === 0
+							? "bg-red-50 border border-red-200 text-red-700"
+							: "bg-green-50 border border-green-200 text-green-700"
+					}`}
+				>
+					{importResult.imported > 0 && (
+						<p className="font-medium">
+							{importResult.imported} item
+							{importResult.imported !== 1 ? "s" : ""} imported.
+						</p>
+					)}
+					{importResult.createdCategories.length > 0 && (
+						<p>New categories: {importResult.createdCategories.join(", ")}</p>
+					)}
+					{importResult.errors.map((err, i) => (
+						// biome-ignore lint/suspicious/noArrayIndexKey: static error list
+						<p key={i} className="text-red-600">
+							{err}
+						</p>
+					))}
+					{importResult.imported === 0 && importResult.errors.length === 0 && (
+						<p>No items found in the CSV.</p>
+					)}
+				</div>
+			)}
+		</div>
+	);
+}
+
 function SettingsPage() {
 	const unit = useWeightUnit();
 	const currency = useCurrency();
@@ -255,6 +345,10 @@ function SettingsPage() {
 				</div>
 			</div>
 
+			<div className="bg-white rounded-xl border border-gray-100 p-5 space-y-6 mt-4">
+				<ImportExportSection />
+			</div>
+
 			{auth?.user && (
 				<div className="bg-white rounded-xl border border-gray-100 p-5 space-y-6 mt-4">
 					<ChangePasswordSection />

src/client/routes/setups/$setupId.tsx

@@ -4,15 +4,13 @@ import { CategoryHeader } from "../../components/CategoryHeader";
 import { ItemCard } from "../../components/ItemCard";
 import { ItemPicker } from "../../components/ItemPicker";
 import { WeightSummaryCard } from "../../components/WeightSummaryCard";
-import { useCurrency } from "../../hooks/useCurrency";
+import { useFormatters } from "../../hooks/useFormatters";
 import {
 	useDeleteSetup,
 	useRemoveSetupItem,
 	useSetup,
 	useUpdateItemClassification,
 } from "../../hooks/useSetups";
-import { useWeightUnit } from "../../hooks/useWeightUnit";
-import { formatPrice, formatWeight } from "../../lib/formatters";
 import { LucideIcon } from "../../lib/iconData";
 
 export const Route = createFileRoute("/setups/$setupId")({
@@ -21,8 +19,7 @@ export const Route = createFileRoute("/setups/$setupId")({
 
 function SetupDetailPage() {
 	const { setupId } = Route.useParams();
-	const unit = useWeightUnit();
-	const currency = useCurrency();
+	const { weight, price } = useFormatters();
 	const navigate = useNavigate();
 	const numericId = Number(setupId);
 	const { data: setup, isLoading } = useSetup(numericId);
@@ -56,13 +53,13 @@ function SetupDetailPage() {
 		);
 	}
 
-	// Compute totals from items
+	// Compute totals from items (multiply by quantity)
 	const totalWeight = setup.items.reduce(
-		(sum, item) => sum + (item.weightGrams ?? 0),
+		(sum, item) => sum + (item.weightGrams ?? 0) * (item.quantity ?? 1),
 		0,
 	);
 	const totalCost = setup.items.reduce(
-		(sum, item) => sum + (item.priceCents ?? 0),
+		(sum, item) => sum + (item.priceCents ?? 0) * (item.quantity ?? 1),
 		0,
 	);
 	const itemCount = setup.items.length;
@@ -127,13 +124,13 @@ function SetupDetailPage() {
 						</span>
 						<span>
 							<span className="font-medium text-gray-700">
-								{formatWeight(totalWeight, unit)}
+								{weight(totalWeight)}
 							</span>{" "}
 							total
 						</span>
 						<span>
 							<span className="font-medium text-gray-700">
-								{formatPrice(totalCost, currency)}
+								{price(totalCost)}
 							</span>{" "}
 							cost
 						</span>
@@ -210,11 +207,13 @@ function SetupDetailPage() {
 							{ items: categoryItems, categoryName, categoryIcon },
 						]) => {
 							const catWeight = categoryItems.reduce(
-								(sum, item) => sum + (item.weightGrams ?? 0),
+								(sum, item) =>
+									sum + (item.weightGrams ?? 0) * (item.quantity ?? 1),
 								0,
 							);
 							const catCost = categoryItems.reduce(
-								(sum, item) => sum + (item.priceCents ?? 0),
+								(sum, item) =>
+									sum + (item.priceCents ?? 0) * (item.quantity ?? 1),
 								0,
 							);
 							return (
@@ -235,6 +234,7 @@ function SetupDetailPage() {
 												name={item.name}
 												weightGrams={item.weightGrams}
 												priceCents={item.priceCents}
+												quantity={item.quantity}
 												categoryName={categoryName}
 												categoryIcon={categoryIcon}
 												imageFilename={item.imageFilename}

src/client/routes/threads/$threadId.tsx

@@ -4,10 +4,13 @@ import { useEffect, useState } from "react";
 import { CandidateCard } from "../../components/CandidateCard";
 import { CandidateListItem } from "../../components/CandidateListItem";
 import { ComparisonTable } from "../../components/ComparisonTable";
+import { SetupImpactSelector } from "../../components/SetupImpactSelector";
 import {
 	useReorderCandidates,
 	useUpdateCandidate,
 } from "../../hooks/useCandidates";
+import { useImpactDeltas } from "../../hooks/useImpactDeltas";
+import { useSetup } from "../../hooks/useSetups";
 import { useThread } from "../../hooks/useThreads";
 import { LucideIcon } from "../../lib/iconData";
 import { useUIStore } from "../../stores/uiStore";
@@ -23,15 +26,21 @@ function ThreadDetailPage() {
 	const openCandidateAddPanel = useUIStore((s) => s.openCandidateAddPanel);
 	const candidateViewMode = useUIStore((s) => s.candidateViewMode);
 	const setCandidateViewMode = useUIStore((s) => s.setCandidateViewMode);
+	const selectedSetupId = useUIStore((s) => s.selectedSetupId);
 	const updateCandidate = useUpdateCandidate(threadId);
 	const reorderMutation = useReorderCandidates(threadId);
+	const { data: setupData } = useSetup(selectedSetupId);
+	const { deltas } = useImpactDeltas(
+		thread?.candidates ?? [],
+		setupData?.items,
+		thread?.categoryId ?? 0,
+	);
 
-	const [tempItems, setTempItems] =
-		useState<typeof thread extends { candidates: infer C } ? C : never | null>(
-			null,
-		);
+	const [tempItems, setTempItems] = useState<
+		NonNullable<typeof thread>["candidates"] | null
+	>(null);
 
-	// Clear tempItems when server data changes (biome-ignore: thread?.candidates is intentional dep)
+	// Clear tempItems when server data changes
 	// biome-ignore lint/correctness/useExhaustiveDependencies: thread?.candidates is the intended trigger
 	useEffect(() => {
 		setTempItems(null);
@@ -78,10 +87,9 @@ function ThreadDetailPage() {
 
 	function handleDragEnd() {
 		if (!tempItems) return;
-		reorderMutation.mutate(
-			{ orderedIds: tempItems.map((c) => c.id) },
-			{ onSettled: () => setTempItems(null) },
-		);
+		reorderMutation.mutate({
+			orderedIds: tempItems.map((c) => c.id),
+		});
 	}
 
 	return (
@@ -120,8 +128,8 @@ function ThreadDetailPage() {
 			)}
 
 			{/* Toolbar: Add candidate + view toggle */}
-			<div className="mb-6 flex items-center gap-3">
-				{isActive && candidateViewMode !== "compare" && (
+			<div className="mb-6 flex items-center gap-3 flex-wrap">
+				{isActive && (
 					<button
 						type="button"
 						onClick={openCandidateAddPanel}
@@ -185,6 +193,7 @@ function ThreadDetailPage() {
 						)}
 					</div>
 				)}
+				<SetupImpactSelector threadStatus={thread.status} />
 			</div>
 
 			{/* Candidates */}
@@ -208,6 +217,7 @@ function ThreadDetailPage() {
 				<ComparisonTable
 					candidates={displayItems}
 					resolvedCandidateId={thread.resolvedCandidateId}
+					deltas={deltas}
 				/>
 			) : candidateViewMode === "list" ? (
 				isActive ? (
@@ -215,8 +225,7 @@ function ThreadDetailPage() {
 						axis="y"
 						values={displayItems}
 						onReorder={setTempItems}
-						onPointerUp={handleDragEnd}
-						className="flex flex-col gap-2"
+						className="flex flex-col"
 					>
 						{displayItems.map((candidate, index) => (
 							<CandidateListItem
@@ -230,6 +239,8 @@ function ThreadDetailPage() {
 										status: newStatus,
 									})
 								}
+								delta={deltas[candidate.id]}
+								onDragEnd={handleDragEnd}
 							/>
 						))}
 					</Reorder.Group>
@@ -247,6 +258,7 @@ function ThreadDetailPage() {
 										status: newStatus,
 									})
 								}
+								delta={deltas[candidate.id]}
 							/>
 						))}
 					</div>
@@ -276,6 +288,7 @@ function ThreadDetailPage() {
 							pros={candidate.pros}
 							cons={candidate.cons}
 							rank={index + 1}
+							delta={deltas[candidate.id]}
 						/>
 					))}
 				</div>

src/client/stores/uiStore.ts

@@ -52,6 +52,10 @@ interface UIState {
 	// Candidate view mode
 	candidateViewMode: "list" | "grid" | "compare";
 	setCandidateViewMode: (mode: "list" | "grid" | "compare") => void;
+
+	// Setup impact preview
+	selectedSetupId: number | null;
+	setSelectedSetupId: (id: number | null) => void;
 }
 
 export const useUIStore = create<UIState>((set) => ({
@@ -111,4 +115,8 @@ export const useUIStore = create<UIState>((set) => ({
 	// Candidate view mode
 	candidateViewMode: "list",
 	setCandidateViewMode: (mode) => set({ candidateViewMode: mode }),
+
+	// Setup impact preview
+	selectedSetupId: null,
+	setSelectedSetupId: (id) => set({ selectedSetupId: id }),
 }));

src/db/schema.ts

@@ -21,6 +21,7 @@ export const items = sqliteTable("items", {
 	productUrl: text("product_url"),
 	imageFilename: text("image_filename"),
 	imageSourceUrl: text("image_source_url"),
+	quantity: integer("quantity").notNull().default(1),
 	createdAt: integer("created_at", { mode: "timestamp" })
 		.notNull()
 		.$defaultFn(() => new Date()),

src/server/index.ts

@@ -1,5 +1,6 @@
 import { Hono } from "hono";
 import { serveStatic } from "hono/bun";
+import { db as prodDb } from "../db/index.ts";
 import { seedDefaults } from "../db/seed.ts";
 import { mcpRoutes } from "./mcp/index.ts";
 import { requireAuth } from "./middleware/auth.ts";
@@ -17,12 +18,28 @@ seedDefaults();
 
 const app = new Hono();
 
+// Centralized error handler
+app.onError((err, c) => {
+	console.error(`[${c.req.method}] ${c.req.path}:`, err);
+	const message =
+		process.env.NODE_ENV === "production"
+			? "Internal server error"
+			: err.message || "Internal server error";
+	return c.json({ error: message }, 500);
+});
+
 // Health check
 app.get("/api/health", (c) => {
 	return c.json({ status: "ok" });
 });
 
-// Auth middleware for write operations (POST/PUT/DELETE) on non-auth routes
+// Inject production database into request context
+app.use("/api/*", async (c, next) => {
+	c.set("db", prodDb);
+	return next();
+});
+
+// Auth middleware for write operations (POST/PUT/PATCH/DELETE) on non-auth routes
 app.use("/api/*", async (c, next) => {
 	// Skip auth routes — they handle their own auth
 	if (c.req.path.startsWith("/api/auth")) return next();

src/server/lib/params.ts

@@ -0,0 +1,9 @@
+/**
+ * Parse a route parameter as a positive integer ID.
+ * Returns the number if valid, or null if the string is not a positive integer.
+ */
+export function parseId(raw: string): number | null {
+	const id = Number(raw);
+	if (!Number.isInteger(id) || id <= 0) return null;
+	return id;
+}

src/server/mcp/index.ts

@@ -2,7 +2,7 @@ import { randomUUID } from "node:crypto";
 import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
 import { WebStandardStreamableHTTPServerTransport } from "@modelcontextprotocol/sdk/server/webStandardStreamableHttp.js";
 import { Hono } from "hono";
-import { db as prodDb } from "@/db/index.ts";
+import { db as prodDb } from "../../db/index.ts";
 import { getUserCount, verifyApiKey } from "../services/auth.service.ts";
 import { getCollectionSummary } from "./resources/collection.ts";
 import {

src/server/mcp/resources/collection.ts

@@ -1,4 +1,4 @@
-import type { db as prodDb } from "@/db/index.ts";
+import type { db as prodDb } from "../../../db/index.ts";
 import { getAllCategories } from "../../services/category.service.ts";
 import { getAllItems } from "../../services/item.service.ts";
 import { getAllSetups } from "../../services/setup.service.ts";

src/server/mcp/tools/categories.ts

@@ -1,4 +1,4 @@
-import type { db as prodDb } from "@/db/index.ts";
+import type { db as prodDb } from "../../../db/index.ts";
 import {
 	createCategory,
 	getAllCategories,

src/server/mcp/tools/items.ts

@@ -1,4 +1,4 @@
-import type { db as prodDb } from "@/db/index.ts";
+import type { db as prodDb } from "../../../db/index.ts";
 import {
 	createItem,
 	deleteItem,

src/server/mcp/tools/setups.ts

@@ -1,4 +1,4 @@
-import type { db as prodDb } from "@/db/index.ts";
+import type { db as prodDb } from "../../../db/index.ts";
 import {
 	createSetup,
 	getAllSetups,

src/server/mcp/tools/threads.ts

@@ -1,4 +1,4 @@
-import type { db as prodDb } from "@/db/index.ts";
+import type { db as prodDb } from "../../../db/index.ts";
 import {
 	createCandidate,
 	createThread,

src/server/middleware/rateLimit.ts

@@ -0,0 +1,53 @@
+import type { Context, Next } from "hono";
+
+interface RateLimitEntry {
+	count: number;
+	resetAt: number;
+}
+
+const store = new Map<string, RateLimitEntry>();
+
+const MAX_ATTEMPTS = 5;
+const WINDOW_MS = 15 * 60 * 1000; // 15 minutes
+
+function getClientIp(c: Context): string {
+	return c.req.header("x-forwarded-for")?.split(",")[0]?.trim() || "unknown";
+}
+
+function cleanup() {
+	const now = Date.now();
+	for (const [key, entry] of store) {
+		if (now >= entry.resetAt) {
+			store.delete(key);
+		}
+	}
+}
+
+export async function rateLimit(c: Context, next: Next) {
+	cleanup();
+
+	const ip = getClientIp(c);
+	const key = `${ip}:${c.req.path}`;
+	const now = Date.now();
+
+	const entry = store.get(key);
+
+	if (!entry || now >= entry.resetAt) {
+		store.set(key, { count: 1, resetAt: now + WINDOW_MS });
+		return next();
+	}
+
+	if (entry.count >= MAX_ATTEMPTS) {
+		const retryAfter = Math.ceil((entry.resetAt - now) / 1000);
+		c.header("Retry-After", String(retryAfter));
+		return c.json({ error: "Too many attempts. Try again later." }, 429);
+	}
+
+	entry.count++;
+	return next();
+}
+
+/** @internal — only for testing */
+export function _resetForTesting() {
+	store.clear();
+}

src/server/routes/auth.ts

@@ -4,7 +4,9 @@ import { Hono } from "hono";
 import { deleteCookie, getCookie, setCookie } from "hono/cookie";
 import { z } from "zod";
 import { users } from "../../db/schema.ts";
+import { parseId } from "../lib/params.ts";
 import { requireAuth } from "../middleware/auth.ts";
+import { rateLimit } from "../middleware/rateLimit.ts";
 import {
 	changePassword,
 	createApiKey,
@@ -59,7 +61,7 @@ app.get("/me", (c) => {
 	return c.json({ user: null, setupRequired });
 });
 
-app.post("/setup", zValidator("json", setupSchema), async (c) => {
+app.post("/setup", rateLimit, zValidator("json", setupSchema), async (c) => {
 	const db = c.get("db");
 
 	if (getUserCount(db) > 0) {
@@ -80,7 +82,7 @@ app.post("/setup", zValidator("json", setupSchema), async (c) => {
 	return c.json({ username: user.username }, 201);
 });
 
-app.post("/login", zValidator("json", loginSchema), async (c) => {
+app.post("/login", rateLimit, zValidator("json", loginSchema), async (c) => {
 	const db = c.get("db");
 	const { username, password } = c.req.valid("json");
 
@@ -186,7 +188,8 @@ app.post(
 
 app.delete("/keys/:id", requireAuth, (c) => {
 	const db = c.get("db");
-	const id = Number(c.req.param("id"));
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid key ID" }, 400);
 	deleteApiKey(db, id);
 	return c.json({ ok: true });
 });

src/server/routes/categories.ts

@@ -4,6 +4,7 @@ import {
 	createCategorySchema,
 	updateCategorySchema,
 } from "../../shared/schemas.ts";
+import { parseId } from "../lib/params.ts";
 import {
 	createCategory,
 	deleteCategory,
@@ -33,7 +34,8 @@ app.put(
 	zValidator("json", updateCategorySchema.omit({ id: true })),
 	(c) => {
 		const db = c.get("db");
-		const id = Number(c.req.param("id"));
+		const id = parseId(c.req.param("id"));
+		if (!id) return c.json({ error: "Invalid category ID" }, 400);
 		const data = c.req.valid("json");
 		const cat = updateCategory(db, id, data);
 		if (!cat) return c.json({ error: "Category not found" }, 404);
@@ -43,7 +45,8 @@ app.put(
 
 app.delete("/:id", (c) => {
 	const db = c.get("db");
-	const id = Number(c.req.param("id"));
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid category ID" }, 400);
 	const result = deleteCategory(db, id);
 
 	if (!result.success) {

src/server/routes/items.ts

@@ -3,9 +3,12 @@ import { join } from "node:path";
 import { zValidator } from "@hono/zod-validator";
 import { Hono } from "hono";
 import { createItemSchema, updateItemSchema } from "../../shared/schemas.ts";
+import { parseId } from "../lib/params.ts";
+import { exportItemsCsv, importItemsCsv } from "../services/csv.service.ts";
 import {
 	createItem,
 	deleteItem,
+	duplicateItem,
 	getAllItems,
 	getItemById,
 	updateItem,
@@ -15,6 +18,27 @@ type Env = { Variables: { db?: any } };
 
 const app = new Hono<Env>();
 
+app.get("/export", (c) => {
+	const db = c.get("db");
+	const csv = exportItemsCsv(db);
+	c.header("Content-Type", "text/csv");
+	c.header("Content-Disposition", 'attachment; filename="gearbox-export.csv"');
+	return c.body(csv);
+});
+
+app.post("/import", async (c) => {
+	const db = c.get("db");
+	const body = await c.req.parseBody();
+	// Accept either "file" (direct) or "image" (via apiUpload helper)
+	const file = body.file ?? body.image;
+	if (!file || typeof file === "string") {
+		return c.json({ error: "No CSV file provided" }, 400);
+	}
+	const content = await file.text();
+	const result = importItemsCsv(db, content);
+	return c.json(result);
+});
+
 app.get("/", (c) => {
 	const db = c.get("db");
 	const items = getAllItems(db);
@@ -23,7 +47,8 @@ app.get("/", (c) => {
 
 app.get("/:id", (c) => {
 	const db = c.get("db");
-	const id = Number(c.req.param("id"));
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid item ID" }, 400);
 	const item = getItemById(db, id);
 	if (!item) return c.json({ error: "Item not found" }, 404);
 	return c.json(item);
@@ -41,7 +66,8 @@ app.put(
 	zValidator("json", updateItemSchema.omit({ id: true })),
 	(c) => {
 		const db = c.get("db");
-		const id = Number(c.req.param("id"));
+		const id = parseId(c.req.param("id"));
+		if (!id) return c.json({ error: "Invalid item ID" }, 400);
 		const data = c.req.valid("json");
 		const item = updateItem(db, id, data);
 		if (!item) return c.json({ error: "Item not found" }, 404);
@@ -49,9 +75,19 @@ app.put(
 	},
 );
 
+app.post("/:id/duplicate", (c) => {
+	const db = c.get("db");
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid item ID" }, 400);
+	const newItem = duplicateItem(db, id);
+	if (!newItem) return c.json({ error: "Item not found" }, 404);
+	return c.json(newItem, 201);
+});
+
 app.delete("/:id", async (c) => {
 	const db = c.get("db");
-	const id = Number(c.req.param("id"));
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid item ID" }, 400);
 	const deleted = deleteItem(db, id);
 	if (!deleted) return c.json({ error: "Item not found" }, 404);
 

src/server/routes/settings.ts

@@ -1,6 +1,5 @@
 import { eq } from "drizzle-orm";
 import { Hono } from "hono";
-import { db as prodDb } from "../../db/index.ts";
 import { settings } from "../../db/schema.ts";
 
 type Env = { Variables: { db?: any } };
@@ -8,7 +7,7 @@ type Env = { Variables: { db?: any } };
 const app = new Hono<Env>();
 
 app.get("/:key", (c) => {
-	const database = c.get("db") ?? prodDb;
+	const database = c.get("db");
 	const key = c.req.param("key");
 	const row = database
 		.select()
@@ -20,7 +19,7 @@ app.get("/:key", (c) => {
 });
 
 app.put("/:key", async (c) => {
-	const database = c.get("db") ?? prodDb;
+	const database = c.get("db");
 	const key = c.req.param("key");
 	const body = await c.req.json<{ value: string }>();
 

src/server/routes/setups.ts

@@ -6,6 +6,7 @@ import {
 	updateClassificationSchema,
 	updateSetupSchema,
 } from "../../shared/schemas.ts";
+import { parseId } from "../lib/params.ts";
 import {
 	createSetup,
 	deleteSetup,
@@ -38,7 +39,8 @@ app.post("/", zValidator("json", createSetupSchema), (c) => {
 
 app.get("/:id", (c) => {
 	const db = c.get("db");
-	const id = Number(c.req.param("id"));
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid setup ID" }, 400);
 	const setup = getSetupWithItems(db, id);
 	if (!setup) return c.json({ error: "Setup not found" }, 404);
 	return c.json(setup);
@@ -46,7 +48,8 @@ app.get("/:id", (c) => {
 
 app.put("/:id", zValidator("json", updateSetupSchema), (c) => {
 	const db = c.get("db");
-	const id = Number(c.req.param("id"));
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid setup ID" }, 400);
 	const data = c.req.valid("json");
 	const setup = updateSetup(db, id, data);
 	if (!setup) return c.json({ error: "Setup not found" }, 404);
@@ -55,7 +58,8 @@ app.put("/:id", zValidator("json", updateSetupSchema), (c) => {
 
 app.delete("/:id", (c) => {
 	const db = c.get("db");
-	const id = Number(c.req.param("id"));
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid setup ID" }, 400);
 	const deleted = deleteSetup(db, id);
 	if (!deleted) return c.json({ error: "Setup not found" }, 404);
 	return c.json({ success: true });
@@ -65,7 +69,8 @@ app.delete("/:id", (c) => {
 
 app.put("/:id/items", zValidator("json", syncSetupItemsSchema), (c) => {
 	const db = c.get("db");
-	const id = Number(c.req.param("id"));
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid setup ID" }, 400);
 	const { itemIds } = c.req.valid("json");
 
 	const setup = getSetupWithItems(db, id);
@@ -80,8 +85,9 @@ app.patch(
 	zValidator("json", updateClassificationSchema),
 	(c) => {
 		const db = c.get("db");
-		const setupId = Number(c.req.param("id"));
-		const itemId = Number(c.req.param("itemId"));
+		const setupId = parseId(c.req.param("id"));
+		const itemId = parseId(c.req.param("itemId"));
+		if (!setupId || !itemId) return c.json({ error: "Invalid ID" }, 400);
 		const { classification } = c.req.valid("json");
 		updateItemClassification(db, setupId, itemId, classification);
 		return c.json({ success: true });
@@ -90,8 +96,9 @@ app.patch(
 
 app.delete("/:id/items/:itemId", (c) => {
 	const db = c.get("db");
-	const setupId = Number(c.req.param("id"));
-	const itemId = Number(c.req.param("itemId"));
+	const setupId = parseId(c.req.param("id"));
+	const itemId = parseId(c.req.param("itemId"));
+	if (!setupId || !itemId) return c.json({ error: "Invalid ID" }, 400);
 	removeSetupItem(db, setupId, itemId);
 	return c.json({ success: true });
 });

src/server/routes/threads.ts

@@ -10,6 +10,7 @@ import {
 	updateCandidateSchema,
 	updateThreadSchema,
 } from "../../shared/schemas.ts";
+import { parseId } from "../lib/params.ts";
 import {
 	createCandidate,
 	createThread,
@@ -45,7 +46,8 @@ app.post("/", zValidator("json", createThreadSchema), (c) => {
 
 app.get("/:id", (c) => {
 	const db = c.get("db");
-	const id = Number(c.req.param("id"));
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid thread ID" }, 400);
 	const thread = getThreadWithCandidates(db, id);
 	if (!thread) return c.json({ error: "Thread not found" }, 404);
 	return c.json(thread);
@@ -53,7 +55,8 @@ app.get("/:id", (c) => {
 
 app.put("/:id", zValidator("json", updateThreadSchema), (c) => {
 	const db = c.get("db");
-	const id = Number(c.req.param("id"));
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid thread ID" }, 400);
 	const data = c.req.valid("json");
 	const thread = updateThread(db, id, data);
 	if (!thread) return c.json({ error: "Thread not found" }, 404);
@@ -62,7 +65,8 @@ app.put("/:id", zValidator("json", updateThreadSchema), (c) => {
 
 app.delete("/:id", async (c) => {
 	const db = c.get("db");
-	const id = Number(c.req.param("id"));
+	const id = parseId(c.req.param("id"));
+	if (!id) return c.json({ error: "Invalid thread ID" }, 400);
 	const deleted = deleteThread(db, id);
 	if (!deleted) return c.json({ error: "Thread not found" }, 404);
 
@@ -82,7 +86,8 @@ app.delete("/:id", async (c) => {
 
 app.post("/:id/candidates", zValidator("json", createCandidateSchema), (c) => {
 	const db = c.get("db");
-	const threadId = Number(c.req.param("id"));
+	const threadId = parseId(c.req.param("id"));
+	if (!threadId) return c.json({ error: "Invalid thread ID" }, 400);
 
 	// Verify thread exists
 	const thread = getThreadWithCandidates(db, threadId);
@@ -98,7 +103,8 @@ app.put(
 	zValidator("json", updateCandidateSchema),
 	(c) => {
 		const db = c.get("db");
-		const candidateId = Number(c.req.param("candidateId"));
+		const candidateId = parseId(c.req.param("candidateId"));
+		if (!candidateId) return c.json({ error: "Invalid candidate ID" }, 400);
 		const data = c.req.valid("json");
 		const candidate = updateCandidate(db, candidateId, data);
 		if (!candidate) return c.json({ error: "Candidate not found" }, 404);
@@ -108,7 +114,8 @@ app.put(
 
 app.delete("/:threadId/candidates/:candidateId", async (c) => {
 	const db = c.get("db");
-	const candidateId = Number(c.req.param("candidateId"));
+	const candidateId = parseId(c.req.param("candidateId"));
+	if (!candidateId) return c.json({ error: "Invalid candidate ID" }, 400);
 	const deleted = deleteCandidate(db, candidateId);
 	if (!deleted) return c.json({ error: "Candidate not found" }, 404);
 
@@ -131,7 +138,8 @@ app.patch(
 	zValidator("json", reorderCandidatesSchema),
 	(c) => {
 		const db = c.get("db");
-		const threadId = Number(c.req.param("id"));
+		const threadId = parseId(c.req.param("id"));
+		if (!threadId) return c.json({ error: "Invalid thread ID" }, 400);
 		const { orderedIds } = c.req.valid("json");
 		const result = reorderCandidates(db, threadId, orderedIds);
 		if (!result.success) return c.json({ error: result.error }, 400);
@@ -143,7 +151,8 @@ app.patch(
 
 app.post("/:id/resolve", zValidator("json", resolveThreadSchema), (c) => {
 	const db = c.get("db");
-	const threadId = Number(c.req.param("id"));
+	const threadId = parseId(c.req.param("id"));
+	if (!threadId) return c.json({ error: "Invalid thread ID" }, 400);
 	const { candidateId } = c.req.valid("json");
 
 	const result = resolveThread(db, threadId, candidateId);

src/server/services/csv.service.ts

@@ -0,0 +1,246 @@
+import { eq } from "drizzle-orm";
+import { db as prodDb } from "../../db/index.ts";
+import { categories, items } from "../../db/schema.ts";
+
+type Db = typeof prodDb;
+
+// ─── CSV serialisation helpers ────────────────────────────────────────────────
+
+function escapeField(value: string | number | null | undefined): string {
+	if (value === null || value === undefined) return "";
+	const str = String(value);
+	// Wrap in quotes if the field contains a comma, double-quote, or newline
+	if (
+		str.includes(",") ||
+		str.includes('"') ||
+		str.includes("\n") ||
+		str.includes("\r")
+	) {
+		return `"${str.replace(/"/g, '""')}"`;
+	}
+	return str;
+}
+
+function buildCsvRow(fields: (string | number | null | undefined)[]): string {
+	return fields.map(escapeField).join(",");
+}
+
+// ─── CSV parsing helpers ───────────────────────────────────────────────────────
+
+function parseCsvLine(line: string): string[] {
+	const fields: string[] = [];
+	let i = 0;
+
+	while (i <= line.length) {
+		if (i === line.length) {
+			// End of line — push empty trailing field only if we were expecting one
+			// (handled by the loop condition above + break below)
+			break;
+		}
+
+		if (line[i] === '"') {
+			// Quoted field
+			let field = "";
+			i++; // skip opening quote
+			while (i < line.length) {
+				if (line[i] === '"') {
+					if (i + 1 < line.length && line[i + 1] === '"') {
+						// Escaped quote
+						field += '"';
+						i += 2;
+					} else {
+						// Closing quote
+						i++;
+						break;
+					}
+				} else {
+					field += line[i];
+					i++;
+				}
+			}
+			fields.push(field);
+			// Skip comma separator
+			if (i < line.length && line[i] === ",") i++;
+		} else {
+			// Unquoted field — read until comma or end of line
+			const start = i;
+			while (i < line.length && line[i] !== ",") i++;
+			fields.push(line.slice(start, i));
+			if (i < line.length) i++; // skip comma
+		}
+	}
+
+	return fields;
+}
+
+function parseCsv(content: string): { headers: string[]; rows: string[][] } {
+	const lines = content.replace(/\r\n/g, "\n").replace(/\r/g, "\n").split("\n");
+	const nonEmpty = lines.filter((l) => l.trim() !== "");
+	if (nonEmpty.length === 0) return { headers: [], rows: [] };
+	const headers = parseCsvLine(nonEmpty[0]);
+	const rows = nonEmpty.slice(1).map(parseCsvLine);
+	return { headers, rows };
+}
+
+// ─── Export ───────────────────────────────────────────────────────────────────
+
+export function exportItemsCsv(db: Db = prodDb): string {
+	const rows = db
+		.select({
+			name: items.name,
+			quantity: items.quantity,
+			weightGrams: items.weightGrams,
+			priceCents: items.priceCents,
+			categoryName: categories.name,
+			notes: items.notes,
+			productUrl: items.productUrl,
+		})
+		.from(items)
+		.innerJoin(categories, eq(items.categoryId, categories.id))
+		.all();
+
+	const header =
+		"name,quantity,weightGrams,priceCents,category,notes,productUrl";
+	const dataLines = rows.map((row) =>
+		buildCsvRow([
+			row.name,
+			row.quantity,
+			row.weightGrams,
+			row.priceCents,
+			row.categoryName,
+			row.notes,
+			row.productUrl,
+		]),
+	);
+
+	return [header, ...dataLines].join("\n");
+}
+
+// ─── Import ───────────────────────────────────────────────────────────────────
+
+export interface ImportResult {
+	imported: number;
+	createdCategories: string[];
+	errors: string[];
+}
+
+export function importItemsCsv(
+	db: Db = prodDb,
+	csvContent: string,
+): ImportResult {
+	const { headers, rows } = parseCsv(csvContent);
+
+	const result: ImportResult = {
+		imported: 0,
+		createdCategories: [],
+		errors: [],
+	};
+
+	if (headers.length === 0) return result;
+
+	// Normalise header names for lookup (case-insensitive)
+	const headerIndex = (name: string): number =>
+		headers.findIndex((h) => h.trim().toLowerCase() === name.toLowerCase());
+
+	const nameIdx = headerIndex("name");
+	const quantityIdx = headerIndex("quantity");
+	const weightIdx = headerIndex("weightGrams");
+	const priceIdx = headerIndex("priceCents");
+	const categoryIdx = headerIndex("category");
+	const notesIdx = headerIndex("notes");
+	const urlIdx = headerIndex("productUrl");
+
+	// Build a local category cache (name → id) seeded from the DB
+	const categoryCache = new Map<string, number>();
+	const existingCategories = db
+		.select({ id: categories.id, name: categories.name })
+		.from(categories)
+		.all();
+	for (const cat of existingCategories) {
+		categoryCache.set(cat.name.toLowerCase(), cat.id);
+	}
+
+	for (let rowNum = 0; rowNum < rows.length; rowNum++) {
+		const row = rows[rowNum];
+		const lineNum = rowNum + 2; // 1-based, +1 for header
+
+		try {
+			const name = nameIdx >= 0 ? row[nameIdx]?.trim() : undefined;
+			if (!name) {
+				result.errors.push(`Row ${lineNum}: missing required field "name"`);
+				continue;
+			}
+
+			// Category resolution
+			let categoryId: number;
+			const rawCategory = categoryIdx >= 0 ? row[categoryIdx]?.trim() : "";
+			const categoryName = rawCategory || "Uncategorized";
+			const cacheKey = categoryName.toLowerCase();
+
+			if (categoryCache.has(cacheKey)) {
+				categoryId = categoryCache.get(cacheKey)!;
+			} else {
+				// Create a new category
+				const inserted = db
+					.insert(categories)
+					.values({ name: categoryName, icon: "package" })
+					.returning()
+					.get();
+				categoryId = inserted.id;
+				categoryCache.set(cacheKey, categoryId);
+				result.createdCategories.push(categoryName);
+			}
+
+			// Parse optional numeric fields
+			const rawQuantity = quantityIdx >= 0 ? row[quantityIdx]?.trim() : "";
+			const quantity = rawQuantity ? Number.parseInt(rawQuantity, 10) : 1;
+			if (rawQuantity && Number.isNaN(quantity)) {
+				result.errors.push(
+					`Row ${lineNum}: invalid quantity "${rawQuantity}", skipping`,
+				);
+				continue;
+			}
+
+			const rawWeight = weightIdx >= 0 ? row[weightIdx]?.trim() : "";
+			const weightGrams = rawWeight ? Number.parseFloat(rawWeight) : null;
+			if (rawWeight && Number.isNaN(weightGrams as number)) {
+				result.errors.push(
+					`Row ${lineNum}: invalid weightGrams "${rawWeight}", skipping`,
+				);
+				continue;
+			}
+
+			const rawPrice = priceIdx >= 0 ? row[priceIdx]?.trim() : "";
+			const priceCents = rawPrice ? Number.parseInt(rawPrice, 10) : null;
+			if (rawPrice && Number.isNaN(priceCents as number)) {
+				result.errors.push(
+					`Row ${lineNum}: invalid priceCents "${rawPrice}", skipping`,
+				);
+				continue;
+			}
+
+			const notes = notesIdx >= 0 ? row[notesIdx]?.trim() || null : null;
+			const productUrl = urlIdx >= 0 ? row[urlIdx]?.trim() || null : null;
+
+			db.insert(items)
+				.values({
+					name,
+					quantity,
+					weightGrams,
+					priceCents,
+					categoryId,
+					notes,
+					productUrl,
+					imageFilename: null,
+					imageSourceUrl: null,
+				})
+				.run();
+
+			result.imported++;
+		} catch (err) {
+			result.errors.push(`Row ${lineNum}: ${(err as Error).message}`);
+		}
+	}
+
+	return result;
+}

src/server/services/item.service.ts

@@ -12,6 +12,7 @@ export function getAllItems(db: Db = prodDb) {
 			name: items.name,
 			weightGrams: items.weightGrams,
 			priceCents: items.priceCents,
+			quantity: items.quantity,
 			categoryId: items.categoryId,
 			notes: items.notes,
 			productUrl: items.productUrl,
@@ -63,6 +64,7 @@ export function createItem(
 			name: data.name,
 			weightGrams: data.weightGrams ?? null,
 			priceCents: data.priceCents ?? null,
+			quantity: data.quantity ?? 1,
 			categoryId: data.categoryId,
 			notes: data.notes ?? null,
 			productUrl: data.productUrl ?? null,
@@ -80,6 +82,7 @@ export function updateItem(
 		name: string;
 		weightGrams: number;
 		priceCents: number;
+		quantity: number;
 		categoryId: number;
 		notes: string;
 		productUrl: string;
@@ -104,6 +107,28 @@ export function updateItem(
 		.get();
 }
 
+export function duplicateItem(db: Db = prodDb, id: number) {
+	const source = db.select().from(items).where(eq(items.id, id)).get();
+
+	if (!source) return null;
+
+	return db
+		.insert(items)
+		.values({
+			name: `${source.name} (copy)`,
+			weightGrams: source.weightGrams,
+			priceCents: source.priceCents,
+			categoryId: source.categoryId,
+			notes: source.notes,
+			productUrl: source.productUrl,
+			imageFilename: source.imageFilename,
+			imageSourceUrl: source.imageSourceUrl,
+			quantity: source.quantity,
+		})
+		.returning()
+		.get();
+}
+
 export function deleteItem(db: Db = prodDb, id: number) {
 	// Get item first (for image cleanup info)
 	const item = db.select().from(items).where(eq(items.id, id)).get();

src/server/services/setup.service.ts

@@ -21,12 +21,12 @@ export function getAllSetups(db: Db = prodDb) {
         WHERE setup_items.setup_id = setups.id
       ), 0)`.as("item_count"),
 			totalWeight: sql<number>`COALESCE((
-        SELECT SUM(items.weight_grams) FROM setup_items
+        SELECT SUM(items.weight_grams * items.quantity) FROM setup_items
         JOIN items ON items.id = setup_items.item_id
         WHERE setup_items.setup_id = setups.id
       ), 0)`.as("total_weight"),
 			totalCost: sql<number>`COALESCE((
-        SELECT SUM(items.price_cents) FROM setup_items
+        SELECT SUM(items.price_cents * items.quantity) FROM setup_items
         JOIN items ON items.id = setup_items.item_id
         WHERE setup_items.setup_id = setups.id
       ), 0)`.as("total_cost"),
@@ -45,6 +45,7 @@ export function getSetupWithItems(db: Db = prodDb, setupId: number) {
 			name: items.name,
 			weightGrams: items.weightGrams,
 			priceCents: items.priceCents,
+			quantity: items.quantity,
 			categoryId: items.categoryId,
 			notes: items.notes,
 			productUrl: items.productUrl,

src/server/services/thread.service.ts

@@ -299,6 +299,7 @@ export function resolveThread(
 				productUrl: candidate.productUrl,
 				imageFilename: candidate.imageFilename,
 				imageSourceUrl: candidate.imageSourceUrl,
+				quantity: 1,
 			})
 			.returning()
 			.get();

src/server/services/totals.service.ts

@@ -10,8 +10,8 @@ export function getCategoryTotals(db: Db = prodDb) {
 			categoryId: items.categoryId,
 			categoryName: categories.name,
 			categoryIcon: categories.icon,
-			totalWeight: sql<number>`COALESCE(SUM(${items.weightGrams}), 0)`,
-			totalCost: sql<number>`COALESCE(SUM(${items.priceCents}), 0)`,
+			totalWeight: sql<number>`COALESCE(SUM(${items.weightGrams} * ${items.quantity}), 0)`,
+			totalCost: sql<number>`COALESCE(SUM(${items.priceCents} * ${items.quantity}), 0)`,
 			itemCount: sql<number>`COUNT(*)`,
 		})
 		.from(items)
@@ -23,8 +23,8 @@ export function getCategoryTotals(db: Db = prodDb) {
 export function getGlobalTotals(db: Db = prodDb) {
 	return db
 		.select({
-			totalWeight: sql<number>`COALESCE(SUM(${items.weightGrams}), 0)`,
-			totalCost: sql<number>`COALESCE(SUM(${items.priceCents}), 0)`,
+			totalWeight: sql<number>`COALESCE(SUM(${items.weightGrams} * ${items.quantity}), 0)`,
+			totalCost: sql<number>`COALESCE(SUM(${items.priceCents} * ${items.quantity}), 0)`,
 			itemCount: sql<number>`COUNT(*)`,
 		})
 		.from(items)

src/shared/schemas.ts

@@ -9,6 +9,7 @@ export const createItemSchema = z.object({
 	productUrl: z.string().url().optional().or(z.literal("")),
 	imageFilename: z.string().optional(),
 	imageSourceUrl: z.string().url().optional().or(z.literal("")),
+	quantity: z.number().int().positive().optional(),
 });
 
 export const updateItemSchema = createItemSchema.partial().extend({

tests/helpers/db.ts

@@ -1,124 +1,17 @@
 import { Database } from "bun:sqlite";
 import { drizzle } from "drizzle-orm/bun-sqlite";
+import { migrate } from "drizzle-orm/bun-sqlite/migrator";
 import * as schema from "../../src/db/schema.ts";
 
 export function createTestDb() {
 	const sqlite = new Database(":memory:");
 	sqlite.run("PRAGMA foreign_keys = ON");
 
-	// Create tables matching the Drizzle schema
-	sqlite.run(`
-    CREATE TABLE categories (
-      id INTEGER PRIMARY KEY AUTOINCREMENT,
-      name TEXT NOT NULL UNIQUE,
-      icon TEXT NOT NULL DEFAULT 'package',
-      created_at INTEGER NOT NULL DEFAULT (unixepoch())
-    )
-  `);
-
-	sqlite.run(`
-    CREATE TABLE items (
-      id INTEGER PRIMARY KEY AUTOINCREMENT,
-      name TEXT NOT NULL,
-      weight_grams REAL,
-      price_cents INTEGER,
-      category_id INTEGER NOT NULL REFERENCES categories(id),
-      notes TEXT,
-      product_url TEXT,
-      image_filename TEXT,
-      image_source_url TEXT,
-      created_at INTEGER NOT NULL DEFAULT (unixepoch()),
-      updated_at INTEGER NOT NULL DEFAULT (unixepoch())
-    )
-  `);
-
-	sqlite.run(`
-    CREATE TABLE threads (
-      id INTEGER PRIMARY KEY AUTOINCREMENT,
-      name TEXT NOT NULL,
-      status TEXT NOT NULL DEFAULT 'active',
-      resolved_candidate_id INTEGER,
-      category_id INTEGER NOT NULL REFERENCES categories(id),
-      created_at INTEGER NOT NULL DEFAULT (unixepoch()),
-      updated_at INTEGER NOT NULL DEFAULT (unixepoch())
-    )
-  `);
-
-	sqlite.run(`
-    CREATE TABLE thread_candidates (
-      id INTEGER PRIMARY KEY AUTOINCREMENT,
-      thread_id INTEGER NOT NULL REFERENCES threads(id) ON DELETE CASCADE,
-      name TEXT NOT NULL,
-      weight_grams REAL,
-      price_cents INTEGER,
-      category_id INTEGER NOT NULL REFERENCES categories(id),
-      notes TEXT,
-      product_url TEXT,
-      image_filename TEXT,
-      image_source_url TEXT,
-      status TEXT NOT NULL DEFAULT 'researching',
-      pros TEXT,
-      cons TEXT,
-      sort_order REAL NOT NULL DEFAULT 0,
-      created_at INTEGER NOT NULL DEFAULT (unixepoch()),
-      updated_at INTEGER NOT NULL DEFAULT (unixepoch())
-    )
-  `);
-
-	sqlite.run(`
-    CREATE TABLE setups (
-      id INTEGER PRIMARY KEY AUTOINCREMENT,
-      name TEXT NOT NULL,
-      created_at INTEGER NOT NULL DEFAULT (unixepoch()),
-      updated_at INTEGER NOT NULL DEFAULT (unixepoch())
-    )
-  `);
-
-	sqlite.run(`
-    CREATE TABLE setup_items (
-      id INTEGER PRIMARY KEY AUTOINCREMENT,
-      setup_id INTEGER NOT NULL REFERENCES setups(id) ON DELETE CASCADE,
-      item_id INTEGER NOT NULL REFERENCES items(id) ON DELETE CASCADE,
-      classification TEXT NOT NULL DEFAULT 'base'
-    )
-  `);
-
-	sqlite.run(`
-    CREATE TABLE settings (
-      key TEXT PRIMARY KEY,
-      value TEXT NOT NULL
-    )
-  `);
-
-	sqlite.run(`
-    CREATE TABLE users (
-      id INTEGER PRIMARY KEY AUTOINCREMENT,
-      username TEXT NOT NULL UNIQUE,
-      password_hash TEXT NOT NULL,
-      created_at INTEGER NOT NULL DEFAULT (unixepoch())
-    )
-  `);
-
-	sqlite.run(`
-    CREATE TABLE sessions (
-      id TEXT PRIMARY KEY,
-      user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
-      expires_at INTEGER NOT NULL
-    )
-  `);
-
-	sqlite.run(`
-    CREATE TABLE api_keys (
-      id INTEGER PRIMARY KEY AUTOINCREMENT,
-      name TEXT NOT NULL,
-      key_hash TEXT NOT NULL,
-      key_prefix TEXT NOT NULL,
-      created_at INTEGER NOT NULL DEFAULT (unixepoch())
-    )
-  `);
-
 	const db = drizzle(sqlite, { schema });
 
+	// Apply all migrations to create tables
+	migrate(db, { migrationsFolder: "./drizzle" });
+
 	// Seed default Uncategorized category
 	db.insert(schema.categories)
 		.values({ name: "Uncategorized", icon: "package" })

tests/lib/impactDeltas.test.ts

@@ -0,0 +1,87 @@
+import { describe, expect, it } from "bun:test";
+import { computeImpactDeltas } from "../../src/client/lib/impactDeltas";
+
+describe("computeImpactDeltas", () => {
+	const candidate = { id: 1, weightGrams: 500, priceCents: 20000 };
+	const candidate2 = { id: 2, weightGrams: 300, priceCents: 15000 };
+
+	it("returns mode 'none' when setupItems is undefined", () => {
+		const result = computeImpactDeltas([candidate], undefined, 1);
+		expect(result.mode).toBe("none");
+		expect(Object.keys(result.deltas)).toHaveLength(0);
+	});
+
+	it("returns replace mode when setup item matches thread category", () => {
+		const setupItems = [
+			{ categoryId: 5, weightGrams: 800, priceCents: 30000, name: "Old Tent" },
+		];
+		const result = computeImpactDeltas([candidate], setupItems, 5);
+		expect(result.mode).toBe("replace");
+		expect(result.deltas[1].weightDelta).toBe(-300); // 500 - 800
+		expect(result.deltas[1].priceDelta).toBe(-10000); // 20000 - 30000
+		expect(result.deltas[1].replacedItemName).toBe("Old Tent");
+	});
+
+	it("returns add mode when no setup item matches thread category", () => {
+		const setupItems = [
+			{ categoryId: 99, weightGrams: 200, priceCents: 5000, name: "Unrelated" },
+		];
+		const result = computeImpactDeltas([candidate], setupItems, 5);
+		expect(result.mode).toBe("add");
+		expect(result.deltas[1].weightDelta).toBe(500);
+		expect(result.deltas[1].priceDelta).toBe(20000);
+		expect(result.deltas[1].replacedItemName).toBeNull();
+	});
+
+	it("returns null weightDelta when candidate weight is null", () => {
+		const nullWeight = { id: 3, weightGrams: null, priceCents: 10000 };
+		const setupItems = [
+			{ categoryId: 5, weightGrams: 200, priceCents: 5000, name: "Item" },
+		];
+		const result = computeImpactDeltas([nullWeight], setupItems, 5);
+		expect(result.deltas[3].weightDelta).toBeNull();
+		expect(result.deltas[3].priceDelta).toBe(5000); // 10000 - 5000
+	});
+
+	it("returns null priceDelta when candidate price is null", () => {
+		const nullPrice = { id: 4, weightGrams: 500, priceCents: null };
+		const setupItems = [
+			{ categoryId: 5, weightGrams: 200, priceCents: 5000, name: "Item" },
+		];
+		const result = computeImpactDeltas([nullPrice], setupItems, 5);
+		expect(result.deltas[4].weightDelta).toBe(300);
+		expect(result.deltas[4].priceDelta).toBeNull();
+	});
+
+	it("handles replace mode with null replaced item weight", () => {
+		const setupItems = [
+			{
+				categoryId: 5,
+				weightGrams: null,
+				priceCents: 5000,
+				name: "Unknown Weight",
+			},
+		];
+		const result = computeImpactDeltas([candidate], setupItems, 5);
+		expect(result.deltas[1].weightDelta).toBe(500); // treat as add for weight
+		expect(result.deltas[1].priceDelta).toBe(15000); // 20000 - 5000
+	});
+
+	it("shows negative delta when candidate is lighter", () => {
+		const setupItems = [
+			{ categoryId: 5, weightGrams: 1000, priceCents: 50000, name: "Heavy" },
+		];
+		const result = computeImpactDeltas([candidate], setupItems, 5);
+		expect(result.deltas[1].weightDelta).toBe(-500);
+		expect(result.deltas[1].priceDelta).toBe(-30000);
+	});
+
+	it("handles multiple candidates", () => {
+		const setupItems = [
+			{ categoryId: 5, weightGrams: 400, priceCents: 18000, name: "Current" },
+		];
+		const result = computeImpactDeltas([candidate, candidate2], setupItems, 5);
+		expect(result.deltas[1].weightDelta).toBe(100); // 500 - 400
+		expect(result.deltas[2].weightDelta).toBe(-100); // 300 - 400
+	});
+});

tests/lib/params.test.ts

@@ -0,0 +1,37 @@
+import { describe, expect, it } from "bun:test";
+import { parseId } from "../../src/server/lib/params";
+
+describe("parseId", () => {
+	it("returns number for valid positive integers", () => {
+		expect(parseId("1")).toBe(1);
+		expect(parseId("42")).toBe(42);
+		expect(parseId("999")).toBe(999);
+	});
+
+	it("returns null for zero", () => {
+		expect(parseId("0")).toBeNull();
+	});
+
+	it("returns null for negative numbers", () => {
+		expect(parseId("-1")).toBeNull();
+		expect(parseId("-100")).toBeNull();
+	});
+
+	it("returns null for decimals", () => {
+		expect(parseId("1.5")).toBeNull();
+		expect(parseId("3.14")).toBeNull();
+	});
+
+	it("returns null for non-numeric strings", () => {
+		expect(parseId("abc")).toBeNull();
+		expect(parseId("")).toBeNull();
+		expect(parseId("hello")).toBeNull();
+		expect(parseId("12abc")).toBeNull();
+	});
+
+	it("returns null for special values", () => {
+		expect(parseId("NaN")).toBeNull();
+		expect(parseId("Infinity")).toBeNull();
+		expect(parseId("-Infinity")).toBeNull();
+	});
+});

tests/middleware/rateLimit.test.ts

@@ -0,0 +1,85 @@
+import { beforeEach, describe, expect, it } from "bun:test";
+import { Hono } from "hono";
+import {
+	_resetForTesting,
+	rateLimit,
+} from "../../src/server/middleware/rateLimit";
+
+function createApp() {
+	const app = new Hono();
+	app.post("/login", rateLimit, (c) => c.json({ ok: true }));
+	app.post("/setup", rateLimit, (c) => c.json({ ok: true }));
+	return app;
+}
+
+function makeRequest(app: Hono, path: string, ip = "127.0.0.1") {
+	return app.request(path, {
+		method: "POST",
+		headers: { "x-forwarded-for": ip },
+	});
+}
+
+describe("rateLimit middleware", () => {
+	beforeEach(() => {
+		_resetForTesting();
+	});
+
+	it("allows first request through", async () => {
+		const app = createApp();
+		const res = await makeRequest(app, "/login");
+		expect(res.status).toBe(200);
+	});
+
+	it("allows up to 5 requests", async () => {
+		const app = createApp();
+		for (let i = 0; i < 5; i++) {
+			const res = await makeRequest(app, "/login");
+			expect(res.status).toBe(200);
+		}
+	});
+
+	it("returns 429 after 5 requests", async () => {
+		const app = createApp();
+		for (let i = 0; i < 5; i++) {
+			await makeRequest(app, "/login");
+		}
+		const res = await makeRequest(app, "/login");
+		expect(res.status).toBe(429);
+		const body = await res.json();
+		expect(body.error).toBe("Too many attempts. Try again later.");
+	});
+
+	it("includes Retry-After header on 429", async () => {
+		const app = createApp();
+		for (let i = 0; i < 5; i++) {
+			await makeRequest(app, "/login");
+		}
+		const res = await makeRequest(app, "/login");
+		expect(res.status).toBe(429);
+		const retryAfter = res.headers.get("Retry-After");
+		expect(retryAfter).toBeTruthy();
+		expect(Number(retryAfter)).toBeGreaterThan(0);
+	});
+
+	it("tracks different IPs independently", async () => {
+		const app = createApp();
+		for (let i = 0; i < 5; i++) {
+			await makeRequest(app, "/login", "10.0.0.1");
+		}
+		const blocked = await makeRequest(app, "/login", "10.0.0.1");
+		expect(blocked.status).toBe(429);
+		const allowed = await makeRequest(app, "/login", "10.0.0.2");
+		expect(allowed.status).toBe(200);
+	});
+
+	it("tracks different paths independently", async () => {
+		const app = createApp();
+		for (let i = 0; i < 5; i++) {
+			await makeRequest(app, "/login");
+		}
+		const blockedLogin = await makeRequest(app, "/login");
+		expect(blockedLogin.status).toBe(429);
+		const allowedSetup = await makeRequest(app, "/setup");
+		expect(allowedSetup.status).toBe(200);
+	});
+});

tests/routes/items.test.ts

@@ -118,4 +118,90 @@ describe("Item Routes", () => {
 		const res = await app.request("/api/items/9999");
 		expect(res.status).toBe(404);
 	});
+
+	it("POST /api/items/:id/duplicate returns 201 with the copy", async () => {
+		const createRes = await app.request("/api/items", {
+			method: "POST",
+			headers: { "Content-Type": "application/json" },
+			body: JSON.stringify({ name: "Tent", categoryId: 1, weightGrams: 1200 }),
+		});
+		const created = await createRes.json();
+
+		const res = await app.request(`/api/items/${created.id}/duplicate`, {
+			method: "POST",
+		});
+
+		expect(res.status).toBe(201);
+		const body = await res.json();
+		expect(body.name).toBe("Tent (copy)");
+		expect(body.weightGrams).toBe(1200);
+		expect(body.id).not.toBe(created.id);
+	});
+
+	it("POST /api/items/999/duplicate returns 404", async () => {
+		const res = await app.request("/api/items/999/duplicate", {
+			method: "POST",
+		});
+		expect(res.status).toBe(404);
+	});
+
+	it("GET /api/items/export returns CSV with correct content-type", async () => {
+		// Create an item first
+		await app.request("/api/items", {
+			method: "POST",
+			headers: { "Content-Type": "application/json" },
+			body: JSON.stringify({
+				name: "Tent",
+				weightGrams: 1200,
+				priceCents: 35000,
+				categoryId: 1,
+			}),
+		});
+
+		const res = await app.request("/api/items/export");
+		expect(res.status).toBe(200);
+		expect(res.headers.get("Content-Type")).toContain("text/csv");
+
+		const text = await res.text();
+		const lines = text.split("\n");
+		expect(lines[0]).toBe(
+			"name,quantity,weightGrams,priceCents,category,notes,productUrl",
+		);
+		expect(lines.length).toBeGreaterThanOrEqual(2);
+		expect(lines[1]).toContain("Tent");
+	});
+
+	it("POST /api/items/import with CSV file creates items", async () => {
+		const csvContent = [
+			"name,quantity,weightGrams,priceCents,category,notes,productUrl",
+			"Sleeping Bag,1,800,25000,Camping,,",
+		].join("\n");
+
+		const formData = new FormData();
+		formData.append(
+			"file",
+			new Blob([csvContent], { type: "text/csv" }),
+			"import.csv",
+		);
+
+		const res = await app.request("/api/items/import", {
+			method: "POST",
+			body: formData,
+		});
+
+		expect(res.status).toBe(200);
+		const body = await res.json();
+		expect(body.imported).toBe(1);
+		expect(body.errors).toHaveLength(0);
+	});
+
+	it("POST /api/items/import with no file returns 400", async () => {
+		const res = await app.request("/api/items/import", {
+			method: "POST",
+			headers: { "Content-Type": "application/json" },
+			body: JSON.stringify({}),
+		});
+
+		expect(res.status).toBe(400);
+	});
 });

tests/routes/params.test.ts

@@ -0,0 +1,81 @@
+import { beforeEach, describe, expect, it } from "bun:test";
+import { Hono } from "hono";
+import { categoryRoutes } from "../../src/server/routes/categories";
+import { itemRoutes } from "../../src/server/routes/items";
+import { setupRoutes } from "../../src/server/routes/setups";
+import { threadRoutes } from "../../src/server/routes/threads";
+import { createTestDb } from "../helpers/db";
+
+function createTestApp() {
+	const db = createTestDb();
+	const app = new Hono();
+	app.use("*", async (c, next) => {
+		c.set("db", db);
+		await next();
+	});
+	app.route("/api/items", itemRoutes);
+	app.route("/api/categories", categoryRoutes);
+	app.route("/api/threads", threadRoutes);
+	app.route("/api/setups", setupRoutes);
+	return app;
+}
+
+describe("Invalid ID parameter handling", () => {
+	let app: Hono;
+
+	beforeEach(() => {
+		app = createTestApp();
+	});
+
+	describe("items", () => {
+		it("GET /api/items/abc returns 400", async () => {
+			const res = await app.request("/api/items/abc");
+			expect(res.status).toBe(400);
+			const body = await res.json();
+			expect(body.error).toContain("Invalid");
+		});
+
+		it("GET /api/items/0 returns 400", async () => {
+			const res = await app.request("/api/items/0");
+			expect(res.status).toBe(400);
+		});
+
+		it("GET /api/items/-1 returns 400", async () => {
+			const res = await app.request("/api/items/-1");
+			expect(res.status).toBe(400);
+		});
+	});
+
+	describe("categories", () => {
+		it("DELETE /api/categories/abc returns 400", async () => {
+			const res = await app.request("/api/categories/abc", {
+				method: "DELETE",
+			});
+			expect(res.status).toBe(400);
+		});
+	});
+
+	describe("threads", () => {
+		it("GET /api/threads/abc returns 400", async () => {
+			const res = await app.request("/api/threads/abc");
+			expect(res.status).toBe(400);
+		});
+
+		it("GET /api/threads/1.5 returns 400", async () => {
+			const res = await app.request("/api/threads/1.5");
+			expect(res.status).toBe(400);
+		});
+	});
+
+	describe("setups", () => {
+		it("GET /api/setups/abc returns 400", async () => {
+			const res = await app.request("/api/setups/abc");
+			expect(res.status).toBe(400);
+		});
+
+		it("GET /api/setups/0 returns 400", async () => {
+			const res = await app.request("/api/setups/0");
+			expect(res.status).toBe(400);
+		});
+	});
+});

tests/services/csv.service.test.ts

@@ -0,0 +1,197 @@
+import { beforeEach, describe, expect, it } from "bun:test";
+import { items } from "../../src/db/schema.ts";
+import {
+	exportItemsCsv,
+	importItemsCsv,
+} from "../../src/server/services/csv.service.ts";
+import { createItem } from "../../src/server/services/item.service.ts";
+import { createTestDb } from "../helpers/db.ts";
+
+describe("CSV Service", () => {
+	let db: ReturnType<typeof createTestDb>;
+
+	beforeEach(() => {
+		db = createTestDb();
+	});
+
+	// ── Export ────────────────────────────────────────────────────────────────
+
+	describe("exportItemsCsv", () => {
+		it("returns correct headers on empty collection", () => {
+			const csv = exportItemsCsv(db);
+			const lines = csv.split("\n");
+			expect(lines[0]).toBe(
+				"name,quantity,weightGrams,priceCents,category,notes,productUrl",
+			);
+			expect(lines).toHaveLength(1);
+		});
+
+		it("exports items with correct values", () => {
+			createItem(db, {
+				name: "Tent",
+				weightGrams: 1200,
+				priceCents: 35000,
+				categoryId: 1,
+				notes: "Ultralight",
+				productUrl: "https://example.com/tent",
+			});
+
+			const csv = exportItemsCsv(db);
+			const lines = csv.split("\n");
+			expect(lines).toHaveLength(2);
+			expect(lines[1]).toContain("Tent");
+			expect(lines[1]).toContain("1200");
+			expect(lines[1]).toContain("35000");
+			expect(lines[1]).toContain("Uncategorized");
+			expect(lines[1]).toContain("Ultralight");
+			expect(lines[1]).toContain("https://example.com/tent");
+		});
+
+		it("properly escapes fields with commas", () => {
+			createItem(db, {
+				name: "Tent, Ultralight",
+				categoryId: 1,
+			});
+
+			const csv = exportItemsCsv(db);
+			const lines = csv.split("\n");
+			expect(lines[1]).toContain('"Tent, Ultralight"');
+		});
+
+		it("properly escapes fields with double quotes", () => {
+			createItem(db, {
+				name: 'He said "great tent"',
+				categoryId: 1,
+			});
+
+			const csv = exportItemsCsv(db);
+			const lines = csv.split("\n");
+			expect(lines[1]).toContain('"He said ""great tent"""');
+		});
+
+		it("exports multiple items", () => {
+			createItem(db, { name: "Tent", categoryId: 1 });
+			createItem(db, { name: "Sleeping Bag", categoryId: 1 });
+
+			const csv = exportItemsCsv(db);
+			const lines = csv.split("\n");
+			expect(lines).toHaveLength(3); // header + 2 items
+		});
+
+		it("exports quantity correctly", () => {
+			// Insert directly to set quantity > 1 (createItem service defaults to 1)
+			db.insert(items)
+				.values({ name: "Bolt", categoryId: 1, quantity: 4 })
+				.run();
+
+			const csv = exportItemsCsv(db);
+			const lines = csv.split("\n");
+			const fields = lines[1].split(",");
+			// quantity is second field
+			expect(fields[1]).toBe("4");
+		});
+	});
+
+	// ── Import ────────────────────────────────────────────────────────────────
+
+	describe("importItemsCsv", () => {
+		it("parses a valid CSV and creates items", () => {
+			const csv = [
+				"name,quantity,weightGrams,priceCents,category,notes,productUrl",
+				"Tent,1,1200,35000,Camping,Ultralight,https://example.com/tent",
+				"Sleeping Bag,1,800,25000,Camping,,",
+			].join("\n");
+
+			const result = importItemsCsv(db, csv);
+			expect(result.imported).toBe(2);
+			expect(result.errors).toHaveLength(0);
+		});
+
+		it("creates missing category and reports it", () => {
+			const csv = [
+				"name,quantity,weightGrams,priceCents,category,notes,productUrl",
+				"Helmet,1,350,12000,Cycling,,",
+			].join("\n");
+
+			const result = importItemsCsv(db, csv);
+			expect(result.imported).toBe(1);
+			expect(result.createdCategories).toContain("Cycling");
+			expect(result.errors).toHaveLength(0);
+		});
+
+		it("uses existing category (case-insensitive) without creating a duplicate", () => {
+			const csv = [
+				"name,quantity,weightGrams,priceCents,category,notes,productUrl",
+				// "uncategorized" should match the seeded "Uncategorized"
+				"Spork,1,,,uncategorized,,",
+			].join("\n");
+
+			const result = importItemsCsv(db, csv);
+			expect(result.imported).toBe(1);
+			expect(result.createdCategories).toHaveLength(0);
+		});
+
+		it("skips rows with no name and records an error", () => {
+			const csv = [
+				"name,quantity,weightGrams,priceCents,category,notes,productUrl",
+				",1,200,,,",
+				"Tent,1,1200,,,",
+			].join("\n");
+
+			const result = importItemsCsv(db, csv);
+			expect(result.imported).toBe(1);
+			expect(result.errors).toHaveLength(1);
+			expect(result.errors[0]).toMatch(/missing required field "name"/);
+		});
+
+		it("defaults quantity to 1 when not provided", () => {
+			const csv = [
+				"name,weightGrams,priceCents,category,notes,productUrl",
+				"Tent,1200,35000,Camping,,",
+			].join("\n");
+
+			const result = importItemsCsv(db, csv);
+			expect(result.imported).toBe(1);
+			expect(result.errors).toHaveLength(0);
+		});
+
+		it("handles optional fields being empty", () => {
+			const csv = [
+				"name,quantity,weightGrams,priceCents,category,notes,productUrl",
+				"Tent,,,,,",
+			].join("\n");
+
+			const result = importItemsCsv(db, csv);
+			expect(result.imported).toBe(1);
+			expect(result.errors).toHaveLength(0);
+		});
+
+		it("handles quoted fields containing commas", () => {
+			const csv = [
+				"name,quantity,weightGrams,priceCents,category,notes,productUrl",
+				'"Tent, Ultralight",1,1200,,,',
+			].join("\n");
+
+			const result = importItemsCsv(db, csv);
+			expect(result.imported).toBe(1);
+			expect(result.errors).toHaveLength(0);
+		});
+
+		it("returns zero imported on empty CSV", () => {
+			const result = importItemsCsv(db, "");
+			expect(result.imported).toBe(0);
+			expect(result.errors).toHaveLength(0);
+		});
+
+		it("uses Uncategorized when category column is empty", () => {
+			const csv = [
+				"name,quantity,weightGrams,priceCents,category,notes,productUrl",
+				"Tent,1,,,,",
+			].join("\n");
+
+			const result = importItemsCsv(db, csv);
+			expect(result.imported).toBe(1);
+			expect(result.createdCategories).toHaveLength(0);
+		});
+	});
+});

tests/services/item.service.test.ts

@@ -2,6 +2,7 @@ import { beforeEach, describe, expect, it } from "bun:test";
 import {
 	createItem,
 	deleteItem,
+	duplicateItem,
 	getAllItems,
 	getItemById,
 	updateItem,
@@ -98,6 +99,41 @@ describe("Item Service", () => {
 		});
 	});
 
+	describe("duplicateItem", () => {
+		it("creates a copy with '(copy)' suffix in name", () => {
+			const original = createItem(db, {
+				name: "Tent",
+				weightGrams: 1200,
+				priceCents: 35000,
+				categoryId: 1,
+				notes: "Ultralight",
+				productUrl: "https://example.com/tent",
+			});
+
+			const copy = duplicateItem(db, original?.id);
+
+			expect(copy).toBeDefined();
+			expect(copy?.name).toBe("Tent (copy)");
+			expect(copy?.weightGrams).toBe(1200);
+			expect(copy?.priceCents).toBe(35000);
+			expect(copy?.categoryId).toBe(1);
+			expect(copy?.notes).toBe("Ultralight");
+			expect(copy?.productUrl).toBe("https://example.com/tent");
+		});
+
+		it("copy has a different ID from the original", () => {
+			const original = createItem(db, { name: "Helmet", categoryId: 1 });
+			const copy = duplicateItem(db, original?.id);
+
+			expect(copy?.id).not.toBe(original?.id);
+		});
+
+		it("returns null for non-existent item", () => {
+			const result = duplicateItem(db, 9999);
+			expect(result).toBeNull();
+		});
+	});
+
 	describe("deleteItem", () => {
 		it("removes item from DB, returns deleted item", () => {
 			const created = createItem(db, {