fix: check table existence before dropping columns in field delete action

https://sonarly.com/issue/18011?type=bug

Deleting a custom object fails with "Migration action 'delete' for 'fieldMetadata' failed" when the workspace schema table doesn't exist but metadata records for the object and its fields still do.

packages/twenty-server/src/engine/twenty-orm/workspace-schema-manager/services/workspace-schema-table-manager.service.ts

@@ -49,6 +49,21 @@ export class WorkspaceSchemaTableManagerService {
     await queryRunner.query(sql);
   }
 
+  async tableExists({
+    queryRunner,
+    schemaName,
+    tableName,
+  }: {
+    queryRunner: QueryRunner;
+    schemaName: string;
+    tableName: string;
+  }): Promise<boolean> {
+    const sql = `SELECT to_regclass('${escapeIdentifier(schemaName)}.${escapeIdentifier(tableName)}') IS NOT NULL AS "exists"`;
+    const result = await queryRunner.query(sql);
+
+    return result?.[0]?.exists === true;
+  }
+
   async renameTable({
     queryRunner,
     schemaName,

packages/twenty-server/src/engine/workspace-manager/workspace-migration/workspace-migration-runner/action-handlers/field/services/delete-field-action-handler.service.ts

@@ -79,6 +79,17 @@ export class DeleteFieldActionHandlerService extends WorkspaceMigrationRunnerAct
       objectMetadata: flatObjectMetadata,
     });
 
+    const tableExists =
+      await this.workspaceSchemaManagerService.tableManager.tableExists({
+        queryRunner,
+        schemaName,
+        tableName,
+      });
+
+    if (!tableExists) {
+      return;
+    }
+
     const columnDefinitions = generateColumnDefinitions({
       flatFieldMetadata,
       flatObjectMetadata,