feat: add pagination support to admin categories endpoint

- Add page/limit query parameters with Zod validation (max 50)
- Update listCategories service to return paginated results
- Response format includes pagination metadata (total, page, limit)
- Matches existing pattern from questions/feedback endpoints

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.claude/settings.json

@@ -0,0 +1,7 @@
+{
+  "enabledPlugins": {
+    "typescript-lsp@claude-plugins-official": true,
+    "claude-md-management@claude-plugins-official": true,
+    "glm-plan-usage@zai-coding-plugins": false
+  }
+}

.claude/settings.local.json

@@ -0,0 +1,15 @@
+{
+  "permissions": {
+    "allow": [
+      "mcp__plugin_ecc_context7__resolve-library-id",
+      "mcp__plugin_ecc_context7__query-docs",
+      "Bash(bun install:*)",
+      "Bash(bun add:*)",
+      "Bash(bunx tsc:*)",
+      "Bash(git status:*)",
+      "Bash(git add:*)",
+      "Bash(git commit:*)",
+      "Bash(bun run:*)"
+    ]
+  }
+}

src/routes/admin/categories.ts

@@ -18,10 +18,32 @@ const updateCategorySchema = z.object({
   status: z.enum(['active', 'inactive']).optional(),
 });
 
+const listCategoriesQuerySchema = z.object({
+  page: z.coerce.number().int().positive().optional().default(1),
+  limit: z.coerce.number().int().positive().max(50).optional().default(20),
+});
+
 export async function adminCategoriesRoutes(app: FastifyInstance): Promise<void> {
-  app.get('/', async () => {
-    const data = await categoryService.listCategories();
-    return { success: true, data, error: null };
+  app.get('/', async (request) => {
+    const parsed = listCategoriesQuerySchema.safeParse(request.query);
+    if (!parsed.success) {
+      return {
+        success: false,
+        data: null,
+        error: {
+          code: 'VALIDATION_ERROR',
+          message: parsed.error.issues[0]?.message ?? 'Invalid query parameters'
+        }
+      };
+    }
+
+    const result = await categoryService.listCategories(parsed.data);
+    return {
+      success: true,
+      data: result.items,
+      pagination: result.pagination,
+      error: null
+    };
   });
 
   app.post('/', async (request) => {

src/services/admin/category-service.ts

@@ -2,8 +2,33 @@ import { db } from '../../db/client.js';
 import { categories, questions } from '../../db/schema.js';
 import { eq, and, sql } from 'drizzle-orm';
 
-export async function listCategories() {
-  return db.select().from(categories).orderBy(categories.sortOrder);
+interface ListOptions {
+  page?: number;
+  limit?: number;
+}
+
+export async function listCategories({ page = 1, limit = 20 }: ListOptions = {}) {
+  const offset = (page - 1) * limit;
+
+  // Get total count
+  const [countResult] = await db
+    .select({ total: sql<number>`COUNT(*)` })
+    .from(categories);
+
+  const total = Number(countResult?.total ?? 0);
+
+  // Get paginated items
+  const items = await db
+    .select()
+    .from(categories)
+    .orderBy(categories.sortOrder)
+    .limit(limit)
+    .offset(offset);
+
+  return {
+    items,
+    pagination: { total, page, limit }
+  };
 }
 
 export async function createCategory(data: { id: string; name: string; slug: string; parentId?: string; sortOrder?: number }) {