refactor: Enhance unique constraint validation across data operations

- Integrated `TableManagementService` to validate unique constraints before insert, update, and upsert actions in various controllers, including `dataflowExecutionController`, `dynamicFormController`, and `tableManagementController`.
- Improved error handling in `errorHandler` to provide detailed messages indicating which field has a unique constraint violation.
- Updated the `formatPgError` utility to extract and display specific column labels for unique constraint violations, enhancing user feedback.
- Adjusted the table schema retrieval to include company-specific nullable and unique constraints, ensuring accurate representation of database rules.

These changes improve data integrity by preventing duplicate entries and enhance user experience through clearer error messages related to unique constraints.

backend-node/src/controllers/dataflowExecutionController.ts

@@ -8,6 +8,7 @@ import { Request, Response } from "express";
 import { AuthenticatedRequest } from "../types/auth";
 import { query } from "../database/db";
 import logger from "../utils/logger";
+import { TableManagementService } from "../services/tableManagementService";
 
 /**
  * 데이터 액션 실행
@@ -81,6 +82,19 @@ async function executeMainDatabaseAction(
       company_code: companyCode,
     };
 
+    // UNIQUE 제약조건 검증 (INSERT/UPDATE/UPSERT 전)
+    if (["insert", "update", "upsert"].includes(actionType.toLowerCase())) {
+      const tms = new TableManagementService();
+      const uniqueViolations = await tms.validateUniqueConstraints(
+        tableName,
+        dataWithCompany,
+        companyCode
+      );
+      if (uniqueViolations.length > 0) {
+        throw new Error(`중복된 값이 존재합니다: ${uniqueViolations.join(", ")}`);
+      }
+    }
+
     switch (actionType.toLowerCase()) {
       case "insert":
         return await executeInsert(tableName, dataWithCompany);