Add applicationId to syncableEntity and fix syncApp deletion (#15170)

## Context
- All flatEntity should extend SyncableEntity
- SyncableEntity should now have applicationId and application relation
- Fix syncApp deletion, should now properly use migration v2 to delete
syncable entities

packages/twenty-server/src/engine/metadata-modules/agent/agent.entity.ts

@@ -12,9 +12,9 @@ import {
 } from 'typeorm';
 
 import { Relation } from 'src/engine/workspace-manager/workspace-sync-metadata/interfaces/relation.interface';
+import { SyncableEntity } from 'src/engine/workspace-manager/workspace-sync/interfaces/syncable-entity.interface';
 
 import { ModelId } from 'src/engine/core-modules/ai/constants/ai-models.const';
-import { ApplicationEntity } from 'src/engine/core-modules/application/application.entity';
 import { Workspace } from 'src/engine/core-modules/workspace/workspace.entity';
 import { ModelConfiguration } from 'src/engine/metadata-modules/agent/types/modelConfiguration';
 
@@ -27,12 +27,15 @@ import { AgentHandoffEntity } from './agent-handoff.entity';
   unique: true,
   where: '"deletedAt" IS NULL',
 })
-export class AgentEntity {
+export class AgentEntity
+  extends SyncableEntity
+  implements Required<AgentEntity>
+{
   @PrimaryGeneratedColumn('uuid')
   id: string;
 
   @Column({ nullable: true, type: 'uuid' })
-  standardId?: string;
+  standardId: string | null;
 
   @Column({ nullable: false })
   name: string;
@@ -58,9 +61,6 @@ export class AgentEntity {
   @Column({ nullable: false, type: 'uuid' })
   workspaceId: string;
 
-  @Column({ nullable: true, type: 'uuid' })
-  applicationId: string | null;
-
   @Column({ default: false })
   isCustom: boolean;
 
@@ -70,13 +70,6 @@ export class AgentEntity {
   @JoinColumn({ name: 'workspaceId' })
   workspace: Relation<Workspace>;
 
-  @ManyToOne(() => ApplicationEntity, (application) => application.agents, {
-    onDelete: 'CASCADE',
-    nullable: true,
-  })
-  @JoinColumn({ name: 'applicationId' })
-  application: Relation<ApplicationEntity> | null;
-
   @OneToMany(() => AgentChatThreadEntity, (chatThread) => chatThread.agent)
   chatThreads: Relation<AgentChatThreadEntity[]>;
 
@@ -93,7 +86,7 @@ export class AgentEntity {
   updatedAt: Date;
 
   @DeleteDateColumn({ type: 'timestamptz' })
-  deletedAt?: Date;
+  deletedAt: Date | null;
 
   @Column({ nullable: true, type: 'jsonb' })
   modelConfiguration: ModelConfiguration;