feat: version selection for runtimes and databases

Backend:
- Add runtimeVersion, phpVersion, dbVersion columns to Application entity
- Add version fields to CreateApplicationDto with validation
- Node.js Dockerfile: use selected version (22/20/18/16) instead of hardcoded 20
- Laravel Dockerfile: use selected PHP version (8.4/8.3/8.2/8.1) instead of 8.3
- WordPress Dockerfile: use selected WP version (6.7/6.6/6.5/6.4) + PHP version
- K8s deployDatabase(): use selected DB version instead of hardcoded postgres:16/mysql:8.0
- K8s restoreDatabaseDump(): match DB image version for restore jobs
- Add dbVersion to ManifestContext interface

Frontend:
- Add runtimeVersion, phpVersion, dbVersion to Application and CreateApplicationDto
- Deploy page: Node.js version dropdown (22/20/18/16)
- Deploy page: Laravel PHP version dropdown (8.4/8.3/8.2/8.1)
- Deploy page: WordPress version + PHP version dropdowns
- Deploy page: PostgreSQL version dropdown (17/16/15/14)
- Deploy page: MySQL version dropdown (9.0/8.4/8.0/5.7)
- Deploy page: auto-set default versions on runtime/DB selection
- Review step: show selected versions
- App detail page: display runtime + DB versions in config and header

backend/src/applications/entities/application.entity.ts

@@ -29,6 +29,15 @@ export class Application {
   @Column({ type: 'enum', enum: DatabaseType, default: DatabaseType.NONE })
   databaseType: DatabaseType;
 
+  @Column({ nullable: true })
+  runtimeVersion: string; // e.g. node: '20', '18', '16' | laravel php: '8.3', '8.2' | wordpress: '6.7', '6.6'
+
+  @Column({ nullable: true })
+  phpVersion: string; // PHP version for Laravel/WordPress (e.g. '8.3', '8.2', '8.1')
+
+  @Column({ nullable: true })
+  dbVersion: string; // e.g. postgres: '17', '16', '15' | mysql: '9.0', '8.4', '8.0'
+
   @Column({ nullable: true })
   dbUsername: string;