docs: update CLAUDE.md with first-time setup instructions and enhance response helpers documentation

CLAUDE.md

@@ -16,6 +16,15 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 All commands run inside ddev: prefix with `ddev exec` unless noted.
 
+### First-time setup
+```bash
+ddev exec composer install
+ddev exec php bin/console lexik:jwt:generate-keypair   # generate JWT keys
+ddev exec php bin/console doctrine:migrations:migrate --no-interaction
+ddev exec yarn install && ddev exec yarn dev
+ddev exec php bin/console app:create-admin             # create first admin user
+```
+
 ### Backend (PHP/Symfony)
 ```bash
 ddev exec php bin/console cache:clear
@@ -28,7 +37,7 @@ ddev exec php bin/console messenger:consume async                      # start q
 ddev exec php bin/phpunit
 ddev exec php bin/phpunit tests/SomeTest.php                          # single test file
 
-# Static analysis
+# Static analysis (level 5, with Symfony + Doctrine extensions)
 ddev exec php vendor/bin/phpstan analyse
 ```
 
@@ -63,13 +72,16 @@ src/
   Shared/Constant/ErrorCodes.php
 ```
 
-**Every controller extends `BaseController`** which provides three response helpers:
+**Every controller extends `BaseController`** which provides four response helpers:
 
 | Method | Shape | When to use |
 |--------|-------|-------------|
 | `$this->success($data)` | `{ success, data: $data }` | Single resource / action |
 | `$this->paginated($items, $total, $page, $limit)` | `{ success, data: $items[], meta: { totalRecords, totalPages, currentPage } }` | Admin list endpoints |
 | `$this->error($code, $message, $status)` | `{ success:false, errors:[{code,message}] }` | All error responses |
+| `$this->validationError($violations)` | `{ success:false, errors:[{code,field,message}] }` HTTP 422 | Input validation failures |
+
+**Domain exceptions:** throw `AppException(ErrorCodes::ERR_XXX, null, $httpStatus)` anywhere in the domain — `ExceptionSubscriber` catches it and calls `$this->error()` automatically. All error codes and their Persian messages live in `src/Shared/Constant/ErrorCodes.php`.
 
 **Critical pitfall — double-nested responses:**  
 `$this->success(['data' => $rep->toArray()])` produces `{ data: { data: {...} } }`, so the frontend must extract with `data?.data?.data`. The `paginated()` helper does NOT nest — it returns `data` as a flat array.
@@ -82,11 +94,17 @@ Single-page app mounted at `/admin/*`:
 assets/admin/
   App.tsx                    # React Router routes
   pages/                     # one file per page
-  components/ui/             # DataTable, Modal, ConfirmDialog, PageHeader, StatusBadge, Pagination
+  components/
+    ui/                      # DataTable, Modal, ConfirmDialog, PageHeader, StatusBadge, Pagination,
+                             #   SearchableSelect, PersianDateInput, PersianCalendar, AppointmentStatusDropdown
+    layout/                  # AdminLayout, Sidebar, Topbar
+  hooks/                     # custom React hooks
   lib/api.ts                 # fetch wrapper (reads JWT from localStorage key: clinicpro-auth)
   lib/utils.ts               # formatRial, formatNumber, formatDate, formatDateTime
   types/index.ts             # all TypeScript interfaces
-  stores/authStore.ts        # Zustand auth store (persisted to localStorage)
+  stores/
+    authStore.ts             # Zustand auth store (persisted to localStorage)
+    uiStore.ts               # sidebar open/close state
 ```
 
 **Data fetching pattern:** TanStack Query v5 (`useQuery` / `useMutation`). Query keys use `['resource-name', page, filters]`.