Fix applications query cartesian product causing read timeouts (#19892)

## Summary

Same fix pattern as #19511 (`rolesPermissions` cartesian product).

The `Settings > Applications` page was hitting query read timeouts in
production. The offending SQL came from
`ApplicationService.findManyApplications` / `findOneApplication`, which
loaded **5 `OneToMany` children** in a single query via TypeORM
`relations`:

```
logicFunctions × agents × frontComponents × objects × applicationVariables
```

Postgres returns the Cartesian product of all five — e.g. 20 logic
functions × 5 agents × 30 front components × 100 objects × 10 variables
= **3M rows for ~165 distinct records**, which trivially exceeds the
read timeout.

## Changes

- **`findManyApplications`** — dropped all `OneToMany` relations. The
frontend `FIND_MANY_APPLICATIONS` query only selects scalar fields and
the `applicationRegistration` ManyToOne, so joining the children was
pure waste at the list level.
- **`findOneApplication`** — kept the cheap `ManyToOne` / `OneToOne`
joins (`packageJsonFile`, `yarnLockFile`, `applicationRegistration`) on
the main query and fetched the 5 `OneToMany` children in parallel via
`Promise.all`, reattaching them on the entity. Same shape as
`WorkspaceRolesPermissionsCacheService.computeForCache` after #19511.
- **`application.module.ts`** — registered the 5 child entity
repositories via `TypeOrmModule.forFeature`.

The other internal caller (`front-component.service.ts →
findOneApplicationOrThrow`) only reads
`application.universalIdentifier`, so the extra parallel single-key
lookups remain far cheaper than the previous 8-way join with row
explosion.

Author: charlesBochet

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

@@ -4,15 +4,28 @@ import { TypeOrmModule } from '@nestjs/typeorm';
 import { ApplicationEntity } from 'src/engine/core-modules/application/application.entity';
 import { ApplicationService } from 'src/engine/core-modules/application/application.service';
 import { WorkspaceFlatApplicationMapCacheService } from 'src/engine/core-modules/application/workspace-flat-application-map-cache.service';
+import { ApplicationVariableEntity } from 'src/engine/core-modules/application/application-variable/application-variable.entity';
 import { FeatureFlagModule } from 'src/engine/core-modules/feature-flag/feature-flag.module';
 import { TwentyConfigModule } from 'src/engine/core-modules/twenty-config/twenty-config.module';
 import { WorkspaceEntity } from 'src/engine/core-modules/workspace/workspace.entity';
+import { AgentEntity } from 'src/engine/metadata-modules/ai/ai-agent/entities/agent.entity';
 import { WorkspaceManyOrAllFlatEntityMapsCacheModule } from 'src/engine/metadata-modules/flat-entity/services/workspace-many-or-all-flat-entity-maps-cache.module';
+import { FrontComponentEntity } from 'src/engine/metadata-modules/front-component/entities/front-component.entity';
+import { LogicFunctionEntity } from 'src/engine/metadata-modules/logic-function/logic-function.entity';
+import { ObjectMetadataEntity } from 'src/engine/metadata-modules/object-metadata/object-metadata.entity';
 import { WorkspaceCacheModule } from 'src/engine/workspace-cache/workspace-cache.module';
 
 @Module({
   imports: [
-    TypeOrmModule.forFeature([ApplicationEntity, WorkspaceEntity]),
+    TypeOrmModule.forFeature([
+      ApplicationEntity,
+      WorkspaceEntity,
+      LogicFunctionEntity,
+      AgentEntity,
+      FrontComponentEntity,
+      ObjectMetadataEntity,
+      ApplicationVariableEntity,
+    ]),
     WorkspaceManyOrAllFlatEntityMapsCacheModule,
     WorkspaceCacheModule,
     TwentyConfigModule,

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

@@ -12,10 +12,15 @@ import {
 } from 'src/engine/core-modules/application/application.exception';
 import { getDefaultApplicationPackageFields } from 'src/engine/core-modules/application/application-package/utils/get-default-application-package-fields.util';
 import { parseAvailablePackagesFromPackageJsonAndYarnLock } from 'src/engine/core-modules/application/application-package/utils/parse-available-packages-from-package-json-and-yarn-lock.util';
+import { ApplicationVariableEntity } from 'src/engine/core-modules/application/application-variable/application-variable.entity';
 import { FileStorageService } from 'src/engine/core-modules/file-storage/file-storage.service';
 import { WorkspaceEntity } from 'src/engine/core-modules/workspace/workspace.entity';
+import { AgentEntity } from 'src/engine/metadata-modules/ai/ai-agent/entities/agent.entity';
 import { ALL_FLAT_ENTITY_MAPS_PROPERTIES } from 'src/engine/metadata-modules/flat-entity/constant/all-flat-entity-maps-properties.constant';
+import { FrontComponentEntity } from 'src/engine/metadata-modules/front-component/entities/front-component.entity';
+import { LogicFunctionEntity } from 'src/engine/metadata-modules/logic-function/logic-function.entity';
 import { logicFunctionCreateHash } from 'src/engine/metadata-modules/logic-function/utils/logic-function-create-hash.utils';
+import { ObjectMetadataEntity } from 'src/engine/metadata-modules/object-metadata/object-metadata.entity';
 import { WorkspaceCacheService } from 'src/engine/workspace-cache/services/workspace-cache.service';
 import { TWENTY_STANDARD_APPLICATION } from 'src/engine/workspace-manager/twenty-standard-application/constants/twenty-standard-applications';
 
@@ -28,6 +33,16 @@ export class ApplicationService {
     private readonly fileStorageService: FileStorageService,
     @InjectRepository(WorkspaceEntity)
     private readonly workspaceRepository: Repository<WorkspaceEntity>,
+    @InjectRepository(LogicFunctionEntity)
+    private readonly logicFunctionRepository: Repository<LogicFunctionEntity>,
+    @InjectRepository(AgentEntity)
+    private readonly agentRepository: Repository<AgentEntity>,
+    @InjectRepository(FrontComponentEntity)
+    private readonly frontComponentRepository: Repository<FrontComponentEntity>,
+    @InjectRepository(ObjectMetadataEntity)
+    private readonly objectMetadataRepository: Repository<ObjectMetadataEntity>,
+    @InjectRepository(ApplicationVariableEntity)
+    private readonly applicationVariableRepository: Repository<ApplicationVariableEntity>,
   ) {}
 
   async findApplicationRoleId(
@@ -119,16 +134,7 @@ export class ApplicationService {
   ): Promise<ApplicationEntity[]> {
     return this.applicationRepository.find({
       where: { workspaceId },
-      relations: [
-        'logicFunctions',
-        'agents',
-        'frontComponents',
-        'objects',
-        'applicationVariables',
-        'packageJsonFile',
-        'yarnLockFile',
-        'applicationRegistration',
-      ],
+      relations: ['applicationRegistration'],
     });
   }
 
@@ -153,19 +159,46 @@ export class ApplicationService {
       ...(isDefined(id) ? { id } : { universalIdentifier }),
     };
 
-    return await this.applicationRepository.findOne({
+    const application = await this.applicationRepository.findOne({
       where,
-      relations: [
-        'logicFunctions',
-        'agents',
-        'frontComponents',
-        'objects',
-        'applicationVariables',
-        'packageJsonFile',
-        'yarnLockFile',
-        'applicationRegistration',
-      ],
+      relations: ['packageJsonFile', 'yarnLockFile', 'applicationRegistration'],
     });
+
+    if (!isDefined(application)) {
+      return null;
+    }
+
+    const [
+      logicFunctions,
+      agents,
+      frontComponents,
+      objects,
+      applicationVariables,
+    ] = await Promise.all([
+      this.logicFunctionRepository.find({
+        where: { applicationId: application.id, workspaceId },
+      }),
+      this.agentRepository.find({
+        where: { applicationId: application.id, workspaceId },
+      }),
+      this.frontComponentRepository.find({
+        where: { applicationId: application.id, workspaceId },
+      }),
+      this.objectMetadataRepository.find({
+        where: { applicationId: application.id, workspaceId },
+      }),
+      this.applicationVariableRepository.find({
+        where: { applicationId: application.id, workspaceId },
+      }),
+    ]);
+
+    application.logicFunctions = logicFunctions;
+    application.agents = agents;
+    application.frontComponents = frontComponents;
+    application.objects = objects;
+    application.applicationVariables = applicationVariables;
+
+    return application;
   }
 
   async findOneApplicationOrThrow({