chore(admin): remove useless config diff (#12545)

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit

- **New Features**
  - Added a GraphQL mutation to validate multiple app configuration updates, returning detailed validation results for each item.
  - Extended the API schema to support validation feedback, enabling client-side checks before applying changes.
  - Introduced a detailed, parameterized error message system for configuration validation errors.
  - Enabled validation of configuration inputs via the admin UI with clear, descriptive error messages.

- **Improvements**
  - Enhanced error reporting with specific, context-rich messages for invalid app configurations.
  - Simplified admin settings UI by removing the confirmation dialog and streamlining save actions.
  - Improved clarity and maintainability of validation logic and error handling components.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/data/commands/import.ts

@@ -4,7 +4,7 @@ import { resolve } from 'node:path';
 import { Logger } from '@nestjs/common';
 import { Command, CommandRunner } from 'nest-commander';
 
-import { ConfigFactory } from '../../base';
+import { ConfigFactory, InvalidAppConfigInput } from '../../base';
 import { Models } from '../../models';
 
 @Command({
@@ -50,7 +50,13 @@ export class ImportConfigCommand extends CommandRunner {
       });
     });
 
-    this.configFactory.validate(forValidation);
+    const errors = this.configFactory.validate(forValidation);
+
+    if (errors?.length) {
+      throw new InvalidAppConfigInput({
+        message: errors.map(error => error.message).join('\n '),
+      });
+    }
 
     // @ts-expect-error null as user id
     await this.models.appConfig.save(null, forSaving);