fix: Enhance error handling and validation messages in form data operations

- Integrated `formatPgError` utility to provide user-friendly error messages based on PostgreSQL error codes during form data operations.
- Updated error responses in `saveFormData`, `saveFormDataEnhanced`, `updateFormData`, and `updateFormDataPartial` to include specific messages based on the company context.
- Improved error handling in the frontend components to display relevant error messages from the server response, ensuring users receive clear feedback on save operations.
- Enhanced the required field validation by incorporating NOT NULL metadata checks across various components, improving the accuracy of form submissions.

These changes improve the overall user experience by providing clearer error messages and ensuring that required fields are properly validated based on both manual settings and database constraints.

frontend/components/screen/InteractiveScreenViewerDynamic.tsx

@@ -558,9 +558,13 @@ export const InteractiveScreenViewerDynamic: React.FC<InteractiveScreenViewerPro
       if (onSave) {
         try {
           await onSave();
-        } catch (error) {
+        } catch (error: any) {
           console.error("저장 오류:", error);
-          toast.error("저장 중 오류가 발생했습니다.");
+          const msg =
+            error?.response?.data?.message ||
+            error?.message ||
+            "저장에 실패했습니다.";
+          toast.error(msg);
         }
         return;
       }
@@ -595,8 +599,12 @@ export const InteractiveScreenViewerDynamic: React.FC<InteractiveScreenViewerPro
           );
 
           toast.success("데이터가 성공적으로 저장되었습니다.");
-        } catch (error) {
-          toast.error("저장 중 오류가 발생했습니다.");
+        } catch (error: any) {
+          const msg =
+            error?.response?.data?.message ||
+            error?.message ||
+            "저장에 실패했습니다.";
+          toast.error(msg);
         }
         return;
       }
@@ -656,8 +664,12 @@ export const InteractiveScreenViewerDynamic: React.FC<InteractiveScreenViewerPro
         } else {
           toast.error(response.message || "저장에 실패했습니다.");
         }
-      } catch (error) {
-        toast.error("저장 중 오류가 발생했습니다.");
+      } catch (error: any) {
+        const msg =
+          error?.response?.data?.message ||
+          error?.message ||
+          "저장에 실패했습니다.";
+        toast.error(msg);
       }
     };
 

frontend/components/screen/SaveModal.tsx

@@ -282,7 +282,8 @@ export const SaveModal: React.FC<SaveModalProps> = ({
           }, 300); // 모달 닫힘 애니메이션 후 실행
         }
       } else {
-        throw new Error(result.message || "저장에 실패했습니다.");
+        const errorMsg = result.message || result.error?.message || "저장에 실패했습니다.";
+        toast.error(errorMsg);
       }
     } catch (error: any) {
       // ❌ 저장 실패 - 모달은 닫히지 않음