feat: [database] codebridge DB connection 적용 (merge 후 재적용)

- 78개 MNG 전용 모델에 $connection = 'codebridge' 재적용
- config/database.php codebridge connection 포함

config/database.php

@@ -63,26 +63,6 @@
             ]) : [],
         ],
 
-        // 코드브릿지엑스 내부 관리 DB (codebridge)
-        'codebridge' => [
-            'driver' => 'mysql',
-            'host' => env('CODEBRIDGE_DB_HOST', env('DB_HOST', '127.0.0.1')),
-            'port' => env('CODEBRIDGE_DB_PORT', env('DB_PORT', '3306')),
-            'database' => env('CODEBRIDGE_DB_DATABASE', 'codebridge'),
-            'username' => env('CODEBRIDGE_DB_USERNAME', env('DB_USERNAME')),
-            'password' => env('CODEBRIDGE_DB_PASSWORD', env('DB_PASSWORD')),
-            'unix_socket' => '',
-            'charset' => 'utf8mb4',
-            'collation' => 'utf8mb4_unicode_ci',
-            'prefix' => '',
-            'prefix_indexes' => true,
-            'strict' => true,
-            'engine' => null,
-            'options' => extension_loaded('pdo_mysql') ? array_filter([
-                PDO::MYSQL_ATTR_SSL_CA => env('MYSQL_ATTR_SSL_CA'),
-            ]) : [],
-        ],
-
         // 통계/알림 DB (sam_stat)
         'sam_stat' => [
             'driver' => 'mysql',