Remove DataSourceService and clean up datasource migration logic (#19532)

## Summary

- **Drop the `objectMetadata.dataSourceId` foreign key and index** via a
1-22 fast instance command — column kept nullable for data preservation
- **Delete `DataSourceService`, `DataSourceModule`, and
`DataSourceException`** — all code now uses `workspace.databaseSchema`
directly
- **Remove `IS_DATASOURCE_MIGRATED` feature flag** from default flags
and all branching logic
- **Simplify workspace/object creation pipelines** —
`WorkspaceManagerService`, `DevSeederService`, and the object creation
action handler no longer route through `DataSourceService`
- **Keep `DataSourceEntity` and the `dataSource` table** for historical
data — entity stripped of all ORM relations

packages/twenty-server/src/engine/workspace-manager/dev-seeder/dev-seeder.module.ts

@@ -9,7 +9,6 @@ import { FeatureFlagModule } from 'src/engine/core-modules/feature-flag/feature-
 import { SdkClientModule } from 'src/engine/core-modules/sdk-client/sdk-client.module';
 import { FileStorageModule } from 'src/engine/core-modules/file-storage/file-storage.module';
 import { WorkspaceEntity } from 'src/engine/core-modules/workspace/workspace.entity';
-import { DataSourceModule } from 'src/engine/metadata-modules/data-source/data-source.module';
 import { FieldMetadataModule } from 'src/engine/metadata-modules/field-metadata/field-metadata.module';
 import { WorkspaceManyOrAllFlatEntityMapsCacheModule } from 'src/engine/metadata-modules/flat-entity/services/workspace-many-or-all-flat-entity-maps-cache.module';
 import { ObjectMetadataEntity } from 'src/engine/metadata-modules/object-metadata/object-metadata.entity';
@@ -37,7 +36,6 @@ import { WorkspaceMigrationModule } from 'src/engine/workspace-manager/workspace
     WorkspaceDataSourceModule,
     WorkspaceCacheStorageModule,
     TypeORMModule,
-    DataSourceModule,
     RoleModule,
     RoleTargetModule,
     UserRoleModule,

packages/twenty-server/src/engine/workspace-manager/dev-seeder/metadata/services/dev-seeder-metadata.service.ts

@@ -3,7 +3,6 @@ import { Injectable } from '@nestjs/common';
 import { FieldMetadataType, RelationType } from 'twenty-shared/types';
 import { isDefined } from 'twenty-shared/utils';
 
-import { type DataSourceEntity } from 'src/engine/metadata-modules/data-source/data-source.entity';
 import { FieldMetadataService } from 'src/engine/metadata-modules/field-metadata/services/field-metadata.service';
 import { WorkspaceManyOrAllFlatEntityMapsCacheService } from 'src/engine/metadata-modules/flat-entity/services/workspace-many-or-all-flat-entity-maps-cache.service';
 import { type FlatEntityMaps } from 'src/engine/metadata-modules/flat-entity/types/flat-entity-maps.type';
@@ -195,11 +194,9 @@ export class DevSeederMetadataService {
   }
 
   public async seed({
-    dataSourceMetadata,
     workspaceId,
     light = false,
   }: {
-    dataSourceMetadata: DataSourceEntity;
     workspaceId: string;
     light?: boolean;
   }) {
@@ -207,7 +204,6 @@ export class DevSeederMetadataService {
 
     for (const obj of config.objects) {
       await this.seedCustomObject({
-        dataSourceId: dataSourceMetadata.id,
         workspaceId,
         objectMetadataSeed: obj.seed,
       });
@@ -231,19 +227,14 @@ export class DevSeederMetadataService {
   }
 
   private async seedCustomObject({
-    dataSourceId,
     workspaceId,
     objectMetadataSeed,
   }: {
-    dataSourceId: string;
     workspaceId: string;
     objectMetadataSeed: ObjectMetadataSeed;
   }): Promise<void> {
     await this.objectMetadataService.createOneObject({
-      createObjectInput: {
-        ...objectMetadataSeed,
-        dataSourceId,
-      },
+      createObjectInput: objectMetadataSeed,
       workspaceId,
     });
   }

packages/twenty-server/src/engine/workspace-manager/dev-seeder/metadata/types/object-metadata-seed.type.ts

@@ -2,7 +2,7 @@ import { type CreateObjectInput } from 'src/engine/metadata-modules/object-metad
 
 export type ObjectMetadataSeed = Omit<
   CreateObjectInput,
-  'workspaceId' | 'dataSourceId' | 'fields'
+  'workspaceId' | 'fields'
 > & {
   skipNameField?: boolean;
 };

packages/twenty-server/src/engine/workspace-manager/dev-seeder/services/dev-seeder.service.ts

@@ -1,14 +1,14 @@
 import { Injectable, Logger } from '@nestjs/common';
-import { InjectDataSource } from '@nestjs/typeorm';
+import { InjectDataSource, InjectRepository } from '@nestjs/typeorm';
 
 import { ALL_METADATA_NAME } from 'twenty-shared/metadata';
-import { DataSource } from 'typeorm';
+import { DataSource, Repository } from 'typeorm';
 
 import { ApplicationRegistrationService } from 'src/engine/core-modules/application/application-registration/application-registration.service';
 import { ApplicationService } from 'src/engine/core-modules/application/application.service';
 import { SdkClientGenerationService } from 'src/engine/core-modules/sdk-client/sdk-client-generation.service';
 import { TwentyConfigService } from 'src/engine/core-modules/twenty-config/twenty-config.service';
-import { DataSourceService } from 'src/engine/metadata-modules/data-source/data-source.service';
+import { WorkspaceEntity } from 'src/engine/core-modules/workspace/workspace.entity';
 import { getMetadataFlatEntityMapsKey } from 'src/engine/metadata-modules/flat-entity/utils/get-metadata-flat-entity-maps-key.util';
 import { getMetadataRelatedMetadataNames } from 'src/engine/metadata-modules/flat-entity/utils/get-metadata-related-metadata-names.util';
 import { ObjectMetadataEntity } from 'src/engine/metadata-modules/object-metadata/object-metadata.entity';
@@ -33,7 +33,6 @@ export class DevSeederService {
     private readonly workspaceCacheStorageService: WorkspaceCacheStorageService,
     private readonly twentyConfigService: TwentyConfigService,
     private readonly workspaceDataSourceService: WorkspaceDataSourceService,
-    private readonly dataSourceService: DataSourceService,
     private readonly twentyStandardApplicationService: TwentyStandardApplicationService,
     private readonly devSeederMetadataService: DevSeederMetadataService,
     private readonly devSeederPermissionsService: DevSeederPermissionsService,
@@ -44,6 +43,8 @@ export class DevSeederService {
     private readonly sdkClientGenerationService: SdkClientGenerationService,
     @InjectDataSource()
     private readonly coreDataSource: DataSource,
+    @InjectRepository(WorkspaceEntity)
+    private readonly workspaceRepository: Repository<WorkspaceEntity>,
   ) {}
 
   public async seedDev(
@@ -74,11 +75,9 @@ export class DevSeederService {
       ['flatApplicationMaps', 'featureFlagsMap'],
     );
 
-    const dataSourceMetadata =
-      await this.dataSourceService.createDataSourceMetadata(
-        workspaceId,
-        schemaName,
-      );
+    await this.workspaceRepository.update(workspaceId, {
+      databaseSchema: schemaName,
+    });
 
     const { workspaceCustomFlatApplication, twentyStandardFlatApplication } =
       await this.applicationService.findWorkspaceTwentyStandardAndCustomApplicationOrThrow(
@@ -101,7 +100,6 @@ export class DevSeederService {
     });
 
     await this.devSeederMetadataService.seed({
-      dataSourceMetadata,
       workspaceId,
       light,
     });
@@ -165,7 +163,7 @@ export class DevSeederService {
     );
 
     await this.devSeederDataService.seed({
-      schemaName: dataSourceMetadata.schema,
+      schemaName,
       workspaceId,
       featureFlags: featureFlagsMap,
       light,