feat(01-02): add Hono API routes with validation, image upload, and integration tests

- Item routes: GET, POST, PUT, DELETE with Zod validation and image cleanup
- Category routes: GET, POST, PUT, DELETE with Uncategorized protection
- Totals route: per-category and global aggregates
- Image upload: multipart file handling with type/size validation
- Routes use DI via Hono context variables for testability
- Integration tests: 10 tests covering all endpoints and edge cases
- All 30 tests passing

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

src/server/routes/categories.ts

@@ -0,0 +1,59 @@
+import { Hono } from "hono";
+import { zValidator } from "@hono/zod-validator";
+import {
+  createCategorySchema,
+  updateCategorySchema,
+} from "../../shared/schemas.ts";
+import {
+  getAllCategories,
+  createCategory,
+  updateCategory,
+  deleteCategory,
+} from "../services/category.service.ts";
+
+type Env = { Variables: { db?: any } };
+
+const app = new Hono<Env>();
+
+app.get("/", (c) => {
+  const db = c.get("db");
+  const cats = getAllCategories(db);
+  return c.json(cats);
+});
+
+app.post("/", zValidator("json", createCategorySchema), (c) => {
+  const db = c.get("db");
+  const data = c.req.valid("json");
+  const cat = createCategory(db, data);
+  return c.json(cat, 201);
+});
+
+app.put(
+  "/:id",
+  zValidator("json", updateCategorySchema.omit({ id: true })),
+  (c) => {
+    const db = c.get("db");
+    const id = Number(c.req.param("id"));
+    const data = c.req.valid("json");
+    const cat = updateCategory(db, id, data);
+    if (!cat) return c.json({ error: "Category not found" }, 404);
+    return c.json(cat);
+  },
+);
+
+app.delete("/:id", (c) => {
+  const db = c.get("db");
+  const id = Number(c.req.param("id"));
+  const result = deleteCategory(db, id);
+
+  if (!result.success) {
+    if (result.error === "Cannot delete the Uncategorized category") {
+      return c.json({ error: result.error }, 400);
+    }
+    return c.json({ error: result.error }, 404);
+  }
+
+  return c.json({ success: true });
+});
+
+export { app as categoryRoutes };