feat: Add City entity methods and migration for title field

- Created a new JSON file for the City entity's AST representation, detailing its methods and properties.
- Added a migration to alter the cities table by adding a nullable title column.

tests/Category/CategoryImportTest.php

@@ -78,6 +78,39 @@ class CategoryImportTest extends ApiTestCase
         $this->assertContains('parent_id', $fields);
     }
 
+    public function testCityTitleAndSocialMediaRoundTripThroughImportExport(): void
+    {
+        $admin = $this->createUser(['ROLE_ADMIN']);
+
+        $this->authJson('POST', '/api/v1/admin/categories/cities/import', $admin, [
+            [
+                'id' => 95001, 'name' => 'شهر تست', 'status' => 1, 'weight' => 0,
+                'site_name' => 'تست نوبت',
+                'title' => 'نوبت‌دهی آنلاین پزشکان شهر تست | تست نوبت',
+                'slogan' => 'شعار تست',
+                'keywords' => 'کلمه یک, کلمه دو',
+                'province_id' => null,
+                'social_media' => ['instagram' => 'test_nobat'],
+            ],
+        ]);
+        $this->assertSame(200, $this->responseCode());
+        $this->assertSame(
+            'نوبت‌دهی آنلاین پزشکان شهر تست | تست نوبت',
+            $this->db()->fetchOne('SELECT title FROM cities WHERE id = 95001'),
+        );
+
+        // export must round-trip lossless in the shape nobat724_front/data/city.json uses
+        $body = $this->authJson('GET', '/api/v1/admin/categories/cities/export', $admin);
+        $row = null;
+        foreach ($body['data'] as $r) {
+            if (($r['id'] ?? null) === 95001) { $row = $r; break; }
+        }
+        $this->assertNotNull($row);
+        $this->assertSame('نوبت‌دهی آنلاین پزشکان شهر تست | تست نوبت', $row['title']);
+        $this->assertSame(['instagram' => 'test_nobat'], $row['social_media']);
+        $this->assertArrayHasKey('province_name', $row);
+    }
+
     public function testNonAdminIsForbidden(): void
     {
         $user = $this->createUser(['ROLE_USER']);