[Dashboards] - Add seeds (#14404)

closes https://github.com/twentyhq/core-team-issues/issues/1440

packages/twenty-server/src/modules/attachment/standard-objects/attachment.workspace-entity.ts

@@ -5,11 +5,13 @@ import { RelationOnDeleteAction } from 'src/engine/metadata-modules/field-metada
 import { RelationType } from 'src/engine/metadata-modules/field-metadata/interfaces/relation-type.interface';
 import { Relation } from 'src/engine/workspace-manager/workspace-sync-metadata/interfaces/relation.interface';
 
+import { FeatureFlagKey } from 'src/engine/core-modules/feature-flag/enums/feature-flag-key.enum';
 import { BaseWorkspaceEntity } from 'src/engine/twenty-orm/base.workspace-entity';
 import { CustomWorkspaceEntity } from 'src/engine/twenty-orm/custom.workspace-entity';
 import { WorkspaceDynamicRelation } from 'src/engine/twenty-orm/decorators/workspace-dynamic-relation.decorator';
 import { WorkspaceEntity } from 'src/engine/twenty-orm/decorators/workspace-entity.decorator';
 import { WorkspaceField } from 'src/engine/twenty-orm/decorators/workspace-field.decorator';
+import { WorkspaceGate } from 'src/engine/twenty-orm/decorators/workspace-gate.decorator';
 import { WorkspaceIsNullable } from 'src/engine/twenty-orm/decorators/workspace-is-nullable.decorator';
 import { WorkspaceIsSystem } from 'src/engine/twenty-orm/decorators/workspace-is-system.decorator';
 import { WorkspaceJoinColumn } from 'src/engine/twenty-orm/decorators/workspace-join-column.decorator';
@@ -169,10 +171,16 @@ export class AttachmentWorkspaceEntity extends BaseWorkspaceEntity {
     inverseSideFieldKey: 'attachments',
     onDelete: RelationOnDeleteAction.CASCADE,
   })
+  @WorkspaceGate({
+    featureFlag: FeatureFlagKey.IS_PAGE_LAYOUT_ENABLED,
+  })
   @WorkspaceIsNullable()
   dashboard: Relation<DashboardWorkspaceEntity> | null;
 
   @WorkspaceJoinColumn('dashboard')
+  @WorkspaceGate({
+    featureFlag: FeatureFlagKey.IS_PAGE_LAYOUT_ENABLED,
+  })
   dashboardId: string | null;
 
   @WorkspaceDynamicRelation({