feat: add WordPress as runtime — Dockerfile, K8s env vars, wp-content PVC, frontend UI

Backend:
- Add WORDPRESS to AppRuntime enum
- Add wordpressDockerfile() using wordpress:6-php8.3-apache base image
  with custom theme/plugin/wp-content merge support
- Add WordPress-specific K8s env vars (WORDPRESS_DB_HOST, WORDPRESS_DB_USER,
  WORDPRESS_DB_PASSWORD, WORDPRESS_DB_NAME, WORDPRESS_TABLE_PREFIX)
- Create wp-content PersistentVolumeClaim (2Gi) for WordPress deployments
- Mount wp-content PVC in deployment container at /var/www/html/wp-content

Frontend:
- Add 'wordpress' to runtime type unions (Application, CreateApplicationDto)
- Add WordPress runtime card in deploy page (port 80, blue icon)
- Auto-select MySQL database when WordPress is chosen, disable other DB options
- Show Persian hint 'وردپرس به MySQL نیاز دارد' when WordPress selected
- Update all runtime icon colors across dashboard, apps, admin/apps pages
  to show blue-600 for WordPress

frontend/src/types/index.ts

@@ -13,7 +13,7 @@ export interface Application {
   id: string;
   name: string;
   description?: string;
-  runtime: 'nodejs' | 'laravel';
+  runtime: 'nodejs' | 'laravel' | 'wordpress';
   databaseType: 'mysql' | 'postgresql' | 'none';
   dbUsername?: string;
   dbPassword?: string;
@@ -87,7 +87,7 @@ export interface AuthResponse {
 export interface CreateApplicationDto {
   name: string;
   description?: string;
-  runtime: 'nodejs' | 'laravel';
+  runtime: 'nodejs' | 'laravel' | 'wordpress';
   databaseType: 'mysql' | 'postgresql' | 'none';
   dbUsername?: string;
   dbPassword?: string;