chore(server): drop unused postgresCredentials feature (#20573)

## Summary

Drops the `postgresCredentials` legacy feature: a never-finished
"postgres proxy" that would have let users query their workspace data
over a standard Postgres connection. Nothing — frontend, e2e, Zapier,
docs, other server code — calls these mutations/query.

## History

- **Introduced** June 2024 (#5767, Thomas Trompette) as "first step for
creating credentials for database proxy", alongside the Postgres FDW /
remote-server work and the custom `twenty-postgres-spilo` image. Planned
follow-ups (provisioning a DB on the proxy, mapping users, exposing it
as a remote server) never landed.
- **Abandoned** January 2026 (#17001, Weiko) when the sibling "remote
integration" feature was removed as a BREAKING CHANGE — "not maintained
for more than a year and never officially launched". The spilo image was
then replaced with vanilla `postgres:16` (#19182, March 2026), retiring
the FDW infrastructure entirely.
- This PR finishes the cleanup: removes the orphaned module, the
`allPostgresCredentials` relation, `JwtTokenTypeEnum.POSTGRES_PROXY` +
payload, the reserved metadata keywords, and adds a 2.5.0 fast instance
command that drops `core.postgresCredentials` (reversible `down`).
Regenerated frontend GraphQL types + SDK metadata client.

## Test plan

- [x] `tsgo --noEmit` clean on twenty-server + twenty-front; lint +
prettier clean on touched files.
- [x] `database:migrate:generate` reports no pending schema diff; server
boots and serves the new schema.

packages/twenty-server/src/database/commands/list-and-delete-orphaned-workspace-entities.command.ts

@@ -17,7 +17,6 @@ import { BillingSubscriptionEntity } from 'src/engine/core-modules/billing/entit
 import { EmailingDomainEntity } from 'src/engine/core-modules/emailing-domain/emailing-domain.entity';
 import { FeatureFlagEntity } from 'src/engine/core-modules/feature-flag/feature-flag.entity';
 import { FileEntity } from 'src/engine/core-modules/file/entities/file.entity';
-import { PostgresCredentialsEntity } from 'src/engine/core-modules/postgres-credentials/postgres-credentials.entity';
 import { PublicDomainEntity } from 'src/engine/core-modules/public-domain/public-domain.entity';
 import { WorkspaceSSOIdentityProviderEntity } from 'src/engine/core-modules/sso/workspace-sso-identity-provider.entity';
 import { UserWorkspaceEntity } from 'src/engine/core-modules/user-workspace/user-workspace.entity';
@@ -103,7 +102,6 @@ const WORKSPACE_RELATED_ENTITIES: EntityTarget<ObjectLiteral>[] = [
   EmailingDomainEntity,
   FeatureFlagEntity,
   FileEntity,
-  PostgresCredentialsEntity,
   PublicDomainEntity,
   WebhookEntity,
   WorkspaceSSOIdentityProviderEntity,

packages/twenty-server/src/database/commands/upgrade-version-command/2-5/2-5-instance-command-fast-1798500000000-drop-postgres-credentials-table.ts

@@ -0,0 +1,36 @@
+import { type QueryRunner } from 'typeorm';
+
+import { RegisteredInstanceCommand } from 'src/engine/core-modules/upgrade/decorators/registered-instance-command.decorator';
+import { type FastInstanceCommand } from 'src/engine/core-modules/upgrade/interfaces/fast-instance-command.interface';
+
+@RegisteredInstanceCommand('2.5.0', 1798500000000)
+export class DropPostgresCredentialsTableFastInstanceCommand
+  implements FastInstanceCommand
+{
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(
+      `ALTER TABLE IF EXISTS "core"."postgresCredentials" DROP CONSTRAINT IF EXISTS "FK_9494639abc06f9c8c3691bf5d22"`,
+    );
+    await queryRunner.query(
+      `DROP TABLE IF EXISTS "core"."postgresCredentials"`,
+    );
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(
+      `CREATE TABLE IF NOT EXISTS "core"."postgresCredentials" (
+        "id" uuid NOT NULL DEFAULT uuid_generate_v4(),
+        "user" character varying NOT NULL,
+        "passwordHash" character varying NOT NULL,
+        "createdAt" TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT now(),
+        "updatedAt" TIMESTAMP WITH TIME ZONE NOT NULL DEFAULT now(),
+        "deletedAt" TIMESTAMP WITH TIME ZONE,
+        "workspaceId" uuid NOT NULL,
+        CONSTRAINT "PK_3f9c4cdf895bfea0a6ea15bdd81" PRIMARY KEY ("id")
+      )`,
+    );
+    await queryRunner.query(
+      `ALTER TABLE "core"."postgresCredentials" ADD CONSTRAINT "FK_9494639abc06f9c8c3691bf5d22" FOREIGN KEY ("workspaceId") REFERENCES "core"."workspace"("id") ON DELETE CASCADE ON UPDATE NO ACTION`,
+    );
+  }
+}

packages/twenty-server/src/database/commands/upgrade-version-command/instance-commands.constant.ts

@@ -39,6 +39,7 @@ import { EncryptApplicationRegistrationVariableSlowInstanceCommand } from 'src/d
 import { EncryptSigningKeyPrivateKeysSlowInstanceCommand } from 'src/database/commands/upgrade-version-command/2-5/2-5-instance-command-slow-1798000007000-encrypt-signing-key-private-keys';
 import { EncryptSensitiveConfigStorageSlowInstanceCommand } from 'src/database/commands/upgrade-version-command/2-5/2-5-instance-command-slow-1798000008000-encrypt-sensitive-config-storage';
 import { AddSubFieldNameToViewSortFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-5/2-5-instance-command-fast-1778502963794-add-sub-field-name-to-view-sort';
+import { DropPostgresCredentialsTableFastInstanceCommand } from 'src/database/commands/upgrade-version-command/2-5/2-5-instance-command-fast-1798500000000-drop-postgres-credentials-table';
 
 export const INSTANCE_COMMANDS = [
   AddViewFieldGroupIdIndexOnViewFieldFastInstanceCommand,
@@ -80,4 +81,5 @@ export const INSTANCE_COMMANDS = [
   EncryptSigningKeyPrivateKeysSlowInstanceCommand,
   EncryptSensitiveConfigStorageSlowInstanceCommand,
   AddSubFieldNameToViewSortFastInstanceCommand,
+  DropPostgresCredentialsTableFastInstanceCommand,
 ];