feat(applications): restore the application custom settings tab (#23256)

## Summary

Restores the application **custom settings tab** feature that was
removed in #22156. This reverts that removal so applications can again
expose a custom settings tab via a front component.

## Changes

- Restore the `SettingsApplicationCustomTab` component and its tab
entry/rendering in `SettingsApplicationDetails`.
- `ApplicationManifestMigrationService` syncs
`settingsCustomTabFrontComponent` from application manifests again
(`syncDefaultRoleAndSettingsCustomTab`), resolving the front component
from `settingsCustomTabFrontComponentUniversalIdentifier`.
- Remove the deprecation annotations added by #22156:
- `ApplicationDTO.settingsCustomTabFrontComponentId` (drop GraphQL
`@deprecated`)
-
`ApplicationManifest.settingsCustomTabFrontComponentUniversalIdentifier`
- the `settingsCustomTabFrontComponentId` column comment on
`ApplicationEntity`
- Regenerate the corresponding GraphQL schema/types to drop the
`@deprecated` reason.

The DB column was never dropped, so no schema migration is required.


---
_Generated by [Claude
Code](https://claude.ai/code/session_01A6aoLa5kZjba9C3uwo6nay)_

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---------

Co-authored-by: Félix Malfait <felix.malfait@gmail.com>

packages/twenty-sdk/src/cli/utilities/build/common/plugins/__tests__/__snapshots__/stub-twenty-sdk-define.plugin.spec.ts.snap

@@ -84,6 +84,7 @@ exports[`stub-twenty-sdk-define plugin > matches the recorded export partition 1
     "definePostInstallLogicFunction",
     "definePreInstallLogicFunction",
     "defineRole",
+    "defineSettingsFrontComponent",
     "defineSkill",
     "defineUninstallLogicFunction",
     "defineView",

packages/twenty-sdk/src/cli/utilities/build/manifest/__tests__/manifest-validate.spec.ts

@@ -227,6 +227,32 @@ describe('manifestValidate', () => {
       expect(result.isValid).toBe(true);
       expect(result.errors).toHaveLength(0);
     });
+
+    it('should not flag a front component referenced via settingsFrontComponent as a duplicate', () => {
+      const frontComponentId = '550e8400-e29b-41d4-a716-446655440050';
+
+      const frontComponent = {
+        universalIdentifier: frontComponentId,
+        name: 'app-settings',
+        componentName: 'AppSettings',
+        sourceComponentPath: 'src/front-components/app-settings.tsx',
+        builtComponentPath: 'dist/app-settings.mjs',
+        builtComponentChecksum: '00000000-0000-4000-8000-000000000000',
+        isHeadless: false,
+      } as unknown as Manifest['frontComponents'][number];
+
+      const result = manifestValidate({
+        ...validManifest,
+        application: {
+          ...validApplication,
+          settingsFrontComponent: { universalIdentifier: frontComponentId },
+        },
+        frontComponents: [frontComponent],
+      });
+
+      expect(result.isValid).toBe(true);
+      expect(result.errors).toHaveLength(0);
+    });
   });
 
   describe('relation field validation', () => {

packages/twenty-sdk/src/cli/utilities/build/manifest/manifest-build.ts

@@ -122,6 +122,7 @@ export const buildManifest = async (
     [];
   const uninstallLogicFunctions: UninstallLogicFunctionApplicationManifest[] =
     [];
+  const settingsFrontComponentUniversalIdentifiers: string[] = [];
   const applicationRoleUniversalIdentifiers: string[] = [];
   const applicationFilePaths: string[] = [];
   const objectsFilePaths: string[] = [];
@@ -377,6 +378,14 @@ export const buildManifest = async (
         frontComponents.push(config);
         frontComponentsFilePaths.push(relativePath);
 
+        if (
+          targetFunctionName === TargetFunction.DefineSettingsFrontComponent
+        ) {
+          settingsFrontComponentUniversalIdentifiers.push(
+            extract.config.universalIdentifier,
+          );
+        }
+
         break;
       }
       case ManifestEntityKey.Views: {
@@ -559,6 +568,12 @@ export const buildManifest = async (
     );
   }
 
+  if (settingsFrontComponentUniversalIdentifiers.length > 1) {
+    errors.push(
+      'Only one settings front component is allowed per application',
+    );
+  }
+
   if (applicationRoleUniversalIdentifiers.length > 1) {
     errors.push('Only one defineApplicationRole is allowed per application');
   }
@@ -611,6 +626,14 @@ export const buildManifest = async (
             ...(uninstallLogicFunctions.length >= 1
               ? { uninstallLogicFunction: uninstallLogicFunctions[0] }
               : {}),
+            ...(settingsFrontComponentUniversalIdentifiers.length >= 1
+              ? {
+                  settingsFrontComponent: {
+                    universalIdentifier:
+                      settingsFrontComponentUniversalIdentifiers[0],
+                  },
+                }
+              : {}),
           };
         })()
       : undefined;

packages/twenty-sdk/src/cli/utilities/build/manifest/manifest-extract-config.ts

@@ -16,6 +16,7 @@ export enum TargetFunction {
   DefineAgent = 'defineAgent',
   DefineConnectionProvider = 'defineConnectionProvider',
   DefineFrontComponent = 'defineFrontComponent',
+  DefineSettingsFrontComponent = 'defineSettingsFrontComponent',
   DefineView = 'defineView',
   DefineViewField = 'defineViewField',
   DefineNavigationMenuItem = 'defineNavigationMenuItem',
@@ -70,6 +71,8 @@ export const TARGET_FUNCTION_TO_ENTITY_KEY_MAPPING: Record<
   [TargetFunction.DefineConnectionProvider]:
     ManifestEntityKey.ConnectionProviders,
   [TargetFunction.DefineFrontComponent]: ManifestEntityKey.FrontComponents,
+  [TargetFunction.DefineSettingsFrontComponent]:
+    ManifestEntityKey.FrontComponents,
   [TargetFunction.DefineView]: ManifestEntityKey.Views,
   [TargetFunction.DefineViewField]: ManifestEntityKey.ViewFields,
   [TargetFunction.DefineNavigationMenuItem]:

packages/twenty-sdk/src/cli/utilities/build/manifest/manifest-validate.ts

@@ -74,7 +74,8 @@ const findUniversalIdentifiers = (obj: object): string[] => {
       key === 'postInstallLogicFunction' ||
       key === 'preInstallLogicFunction' ||
       key === 'uninstallLogicFunction' ||
-      key === 'onConnectLogicFunction'
+      key === 'onConnectLogicFunction' ||
+      key === 'settingsFrontComponent'
     ) {
       continue;
     }