fix: [pmis] validation exists 규칙에 codebridge connection 지정

- exists:pmis_* → exists:codebridge.pmis_* 변경 (4개 컨트롤러, 10곳)
- 원인: 모델은 codebridge connection이지만 validation은 기본 connection(sam) 사용

app/Http/Controllers/Juil/PmisArchiveController.php

@@ -145,7 +145,7 @@ public function fileList(Request $request): JsonResponse
     public function fileStore(Request $request): JsonResponse
     {
         $request->validate([
-            'folder_id' => 'required|integer|exists:pmis_archive_folders,id',
+            'folder_id' => 'required|integer|exists:codebridge.pmis_archive_folders,id',
             'files' => 'required|array|min:1',
             'files.*' => 'file|max:51200',
             'title' => 'nullable|string|max:300',