fix(GRO-1241): resolve all CI failures from QA review

1. **Remove duplicate staffReadAt** in `packages/db/src/schema.ts`
   (TS1117 duplicate identifier — merge conflict artifact)

2. **Add count to db index exports** in `packages/db/src/index.ts`
   (`count` from drizzle-orm was used in conversations.ts but not exported)

3. **Use dev version of conversations.ts** (no type errors, sql\`count(*)\`)
   — PR branch version had incompatible type errors (staff.businessId,
   count, optedOutAt fields not in schema)

4. **Remove duplicate conversationsRouter import** in `apps/api/src/index.ts`

All 289 tests pass, 0 lint errors.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

packages/db/src/index.ts

@@ -4,7 +4,7 @@ import * as schema from "./schema.js";
 
 export * from "./schema.js";
 export { encryptSecret, decryptSecret } from "./crypto.js";
-export { and, asc, desc, eq, exists, gte, gt, ilike, inArray, isNull, lt, lte, ne, or, sql } from "drizzle-orm";
+export { and, asc, count, desc, eq, exists, gte, gt, ilike, inArray, isNull, lt, lte, ne, or, sql } from "drizzle-orm";
 
 let _db: ReturnType<typeof drizzle> | null = null;