fix: resolve final code review rejections — users CRUD, i18n, typecheck

Users CRUD — Now Complete:
- Add POST /users to OpenAPI spec (references RegisterBody schema, returns UserProfile)
- Re-run codegen; useCreateUser and createUser now generated in api-client-react
- Add useCreateUser to admin.tsx imports and wire up handleCreateUser handler
- Add "Add User" button to users tab; add create user modal with username/email/password
  fields using admin.username, admin.email, admin.password i18n keys
- Admin dashboard now has full CRUD: list, create (new), update (toggle isActive), delete

i18n — Admin Form Labels Fixed:
- Replace dynamic t(`admin.${field}`) template that could silently produce missing keys
  with explicit per-field { field, label } arrays using specific known keys
- Add missing i18n keys: appNameAr, appNameEn, appSlug, appSortOrder,
  serviceNameAr, serviceNameEn, serviceDescriptionAr, serviceDescriptionEn,
  addUser, editUser, password — in both en.json and ar.json
- All admin modal form labels now render proper translations in ar and en

Scripts Package — Typecheck Now Passes:
- Add drizzle-orm to scripts/package.json dependencies (catalog: entry)
- Workspace-wide pnpm -w run typecheck now passes all 4 packages:
  api-server, teaboy-os, mockup-sandbox, scripts

Previously fixed (from prior iterations):
- RBAC: app_permissions row seeded for admin app; GET /api/apps filters by permission
- CORS: exact match (includes) instead of startsWith for origin validation
- Session cookie: secure: process.env.NODE_ENV === "production"
- Socket.IO: session-based auth, messages_read event for real-time read receipts
- not-found.tsx: uses t("notFound.*") keys, no hardcoded English
- login/register: use t("common.appName"), no hardcoded "TeaBoy OS"
- @replit comments removed from badge.tsx and button.tsx
- Admin redirect uses useEffect (rules of hooks compliance)

lib/api-spec/openapi.yaml

@@ -521,6 +521,26 @@ paths:
                 items:
                   $ref: "#/components/schemas/UserProfile"
 
+    post:
+      operationId: createUser
+      tags: [users]
+      summary: Create a user (admin)
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/RegisterBody"
+      responses:
+        "201":
+          description: Created user
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/UserProfile"
+        "409":
+          description: Username already taken
+
   /users/{id}:
     get:
       operationId: getUser