test(01-02): add failing tests for item, category, and totals services

- Item CRUD tests: create, getAll, getById, update, delete
- Category CRUD tests: create, getAll, update, delete with reassignment
- Totals tests: per-category and global aggregates

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

tests/services/category.service.test.ts

@@ -0,0 +1,98 @@
+import { describe, it, expect, beforeEach } from "bun:test";
+import { createTestDb } from "../helpers/db.ts";
+import {
+  getAllCategories,
+  createCategory,
+  updateCategory,
+  deleteCategory,
+} from "../../src/server/services/category.service.ts";
+import { createItem } from "../../src/server/services/item.service.ts";
+import { items } from "../../src/db/schema.ts";
+import { eq } from "drizzle-orm";
+
+describe("Category Service", () => {
+  let db: ReturnType<typeof createTestDb>;
+
+  beforeEach(() => {
+    db = createTestDb();
+  });
+
+  describe("createCategory", () => {
+    it("creates with name and emoji", () => {
+      const cat = createCategory(db, { name: "Shelter", emoji: "\u{26FA}" });
+
+      expect(cat).toBeDefined();
+      expect(cat!.id).toBeGreaterThan(0);
+      expect(cat!.name).toBe("Shelter");
+      expect(cat!.emoji).toBe("\u{26FA}");
+    });
+
+    it("uses default emoji if not provided", () => {
+      const cat = createCategory(db, { name: "Cooking" });
+
+      expect(cat).toBeDefined();
+      expect(cat!.emoji).toBe("\u{1F4E6}");
+    });
+  });
+
+  describe("getAllCategories", () => {
+    it("returns all categories", () => {
+      createCategory(db, { name: "Shelter", emoji: "\u{26FA}" });
+      createCategory(db, { name: "Cooking", emoji: "\u{1F373}" });
+
+      const all = getAllCategories(db);
+      // Includes seeded Uncategorized + 2 new
+      expect(all.length).toBeGreaterThanOrEqual(3);
+    });
+  });
+
+  describe("updateCategory", () => {
+    it("renames category", () => {
+      const cat = createCategory(db, { name: "Shelter", emoji: "\u{26FA}" });
+      const updated = updateCategory(db, cat!.id, { name: "Sleep System" });
+
+      expect(updated).toBeDefined();
+      expect(updated!.name).toBe("Sleep System");
+      expect(updated!.emoji).toBe("\u{26FA}");
+    });
+
+    it("changes emoji", () => {
+      const cat = createCategory(db, { name: "Shelter", emoji: "\u{26FA}" });
+      const updated = updateCategory(db, cat!.id, { emoji: "\u{1F3E0}" });
+
+      expect(updated).toBeDefined();
+      expect(updated!.emoji).toBe("\u{1F3E0}");
+    });
+
+    it("returns null for non-existent id", () => {
+      const result = updateCategory(db, 9999, { name: "Ghost" });
+      expect(result).toBeNull();
+    });
+  });
+
+  describe("deleteCategory", () => {
+    it("reassigns items to Uncategorized (id=1) then deletes", () => {
+      const shelter = createCategory(db, { name: "Shelter", emoji: "\u{26FA}" });
+      createItem(db, { name: "Tent", categoryId: shelter!.id });
+      createItem(db, { name: "Tarp", categoryId: shelter!.id });
+
+      const result = deleteCategory(db, shelter!.id);
+      expect(result.success).toBe(true);
+
+      // Items should now be in Uncategorized (id=1)
+      const reassigned = db
+        .select()
+        .from(items)
+        .where(eq(items.categoryId, 1))
+        .all();
+      expect(reassigned).toHaveLength(2);
+      expect(reassigned.map((i) => i.name).sort()).toEqual(["Tarp", "Tent"]);
+    });
+
+    it("cannot delete Uncategorized (id=1)", () => {
+      const result = deleteCategory(db, 1);
+      expect(result.success).toBe(false);
+      expect(result.error).toBeDefined();
+    });
+  });
+});