feat(applications): remove the application custom settings tab (#22156)

## Summary

Removes the application **custom settings tab** feature. This is one
half of #22059, split out so it can be reviewed/merged independently
from the variable-types enrichment.

## Changes

- Remove the `SettingsApplicationCustomTab` component and its tab
entry/rendering in `SettingsApplicationDetails`.
- Stop syncing `settingsCustomTabFrontComponent` from application
manifests — `ApplicationManifestMigrationService` now only syncs the
default role.
- Deprecate the now-unused fields (kept for backward compatibility, no
longer read or synced):
- `ApplicationDTO.settingsCustomTabFrontComponentId` (GraphQL
`@deprecated`)
-
`ApplicationManifest.settingsCustomTabFrontComponentUniversalIdentifier`
- the `settingsCustomTabFrontComponentId` column comment on
`ApplicationEntity`

The DB column is intentionally **not dropped**, so existing
installations upgrade cleanly.

packages/twenty-server/src/engine/core-modules/application/application-manifest/application-manifest-migration.service.ts

@@ -257,7 +257,7 @@ export class ApplicationManifestMigrationService {
     );
 
     if (!dryRun) {
-      await this.syncDefaultRoleAndSettingsCustomTab({
+      await this.syncDefaultRole({
         manifest,
         workspaceId,
         ownerFlatApplication,
@@ -270,7 +270,7 @@ export class ApplicationManifestMigrationService {
     };
   }
 
-  private async syncDefaultRoleAndSettingsCustomTab({
+  private async syncDefaultRole({
     manifest,
     workspaceId,
     ownerFlatApplication,
@@ -279,13 +279,10 @@ export class ApplicationManifestMigrationService {
     workspaceId: string;
     ownerFlatApplication: FlatApplication;
   }) {
-    const {
-      flatRoleMaps: refreshedFlatRoleMaps,
-      flatFrontComponentMaps: refreshedFlatFrontComponentMaps,
-    } = await this.workspaceCacheService.getOrRecompute(workspaceId, [
-      'flatRoleMaps',
-      'flatFrontComponentMaps',
-    ]);
+    const { flatRoleMaps: refreshedFlatRoleMaps } =
+      await this.workspaceCacheService.getOrRecompute(workspaceId, [
+        'flatRoleMaps',
+      ]);
 
     let defaultRoleId: string | null = null;
 
@@ -310,31 +307,11 @@ export class ApplicationManifestMigrationService {
       }
     }
 
-    let settingsCustomTabFrontComponentId: string | null = null;
-
-    const settingsCustomTabUniversalIdentifier =
-      manifest.application.settingsCustomTabFrontComponentUniversalIdentifier;
-
-    if (isDefined(settingsCustomTabUniversalIdentifier)) {
-      const flatFrontComponent = findFlatEntityByUniversalIdentifier({
-        flatEntityMaps: refreshedFlatFrontComponentMaps,
-        universalIdentifier: settingsCustomTabUniversalIdentifier,
+    if (isDefined(defaultRoleId)) {
+      await this.applicationService.update(ownerFlatApplication.id, {
+        workspaceId,
+        defaultRoleId,
       });
-
-      if (!isDefined(flatFrontComponent)) {
-        throw new ApplicationException(
-          `Failed to resolve front component for settingsCustomTabFrontComponentUniversalIdentifier ${settingsCustomTabUniversalIdentifier}`,
-          ApplicationExceptionCode.ENTITY_NOT_FOUND,
-        );
-      }
-
-      settingsCustomTabFrontComponentId = flatFrontComponent.id;
     }
-
-    await this.applicationService.update(ownerFlatApplication.id, {
-      workspaceId,
-      settingsCustomTabFrontComponentId,
-      ...(isDefined(defaultRoleId) ? { defaultRoleId } : {}),
-    });
   }
 }

packages/twenty-server/src/engine/core-modules/application/application.entity.ts

@@ -102,6 +102,11 @@ export class ApplicationEntity extends WorkspaceRelatedEntity {
   @Field(() => RoleDTO, { nullable: true })
   defaultRole: RoleDTO | null;
 
+  /**
+   * @deprecated Custom settings tabs are no longer supported. The column is
+   * kept (not dropped) so existing installations upgrade cleanly, but the
+   * value is no longer read or synced from manifests.
+   */
   @Column({ nullable: true, type: 'uuid' })
   settingsCustomTabFrontComponentId: string | null;
 

packages/twenty-server/src/engine/core-modules/application/dtos/application.dto.ts

@@ -86,9 +86,17 @@ export class ApplicationDTO {
   @Field({ nullable: true })
   defaultRoleId?: string;
 
+  /**
+   * @deprecated Custom settings tabs are no longer supported. Kept for
+   * backward compatibility with existing installations; the value is ignored.
+   */
   @IsOptional()
   @IsUUID()
-  @Field(() => UUIDScalarType, { nullable: true })
+  @Field(() => UUIDScalarType, {
+    nullable: true,
+    deprecationReason:
+      'Custom settings tabs are no longer supported. This field is ignored.',
+  })
   settingsCustomTabFrontComponentId?: string;
 
   @IsOptional()