Fix AI model registry staleness on self-hosted instances (#19427)

## Summary

Fixes #19422.

Self-hosted users hitting "No AI models are available" after configuring
API keys via the admin panel were victims of a stale
`AiModelRegistryService` cache. Only the four `addAiProvider` /
`removeAiProvider` / `addModelToProvider` / `removeModelFromProvider`
mutations called `refreshRegistry()` — setting an API key through
`set/update/deleteDatabaseConfigVariable` left the registry pointing at
the pre-mutation provider state.

Rather than patch each mutation site (and re-introduce the same class of
bug on the next one), the registry now invalidates lazily based on the
LLM config-group hash, mirroring the pattern `WebSearchDriverFactory`
already uses via `DriverFactoryBase`. Any mutation to an LLM-tagged
config variable is picked up automatically on the next read — callers
never have to remember to refresh.

- Extracted `getConfigGroupHash` into a shared util reused by both
`DriverFactoryBase` and `AiModelRegistryService` (and switched the hash
to `JSON.stringify` so object-typed config vars like `AI_PROVIDERS`
actually contribute meaningfully).
- `AiModelRegistryService` gates all internal `Map` access behind
private getters that call `ensureFresh()`, so future read paths can't
accidentally observe stale state. Build path uses underscored backing
fields directly to avoid recursing.
- Dropped the now-redundant `refreshRegistry()` public method and its
four call sites in `admin-panel.resolver.ts`.

## Test plan

- [x] `nx typecheck twenty-server` passes
- [x] Existing admin-panel + ai-models specs pass (79 tests)
- [ ] Manual: on a self-hosted instance, set `OPENAI_API_KEY` (or
another provider key) via the admin panel `setDatabaseConfigVariable`
mutation and confirm AI features work without a server restart
- [ ] Manual: existing flows (`addAiProvider`, `addModelToProvider`,
etc.) still pick up new providers on the next read

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

packages/twenty-server/src/engine/core-modules/email/__tests__/email-driver.factory.spec.ts

@@ -2,15 +2,20 @@ import { Test, type TestingModule } from '@nestjs/testing';
 
 import { EmailDriverFactory } from 'src/engine/core-modules/email/email-driver.factory';
 import { EmailDriver } from 'src/engine/core-modules/email/enums/email-driver.enum';
+import { ConfigGroupHashService } from 'src/engine/core-modules/twenty-config/services/config-group-hash.service';
 import { TwentyConfigService } from 'src/engine/core-modules/twenty-config/twenty-config.service';
 
 describe('EmailDriverFactory', () => {
   let factory: EmailDriverFactory;
   let twentyConfigService: TwentyConfigService;
+  let configGroupHashService: ConfigGroupHashService;
 
   const mockTwentyConfigService = {
     get: jest.fn(),
   };
+  const mockConfigGroupHashService = {
+    computeHash: jest.fn().mockReturnValue(''),
+  };
 
   beforeEach(async () => {
     const module: TestingModule = await Test.createTestingModule({
@@ -20,11 +25,18 @@ describe('EmailDriverFactory', () => {
           provide: TwentyConfigService,
           useValue: mockTwentyConfigService,
         },
+        {
+          provide: ConfigGroupHashService,
+          useValue: mockConfigGroupHashService,
+        },
       ],
     }).compile();
 
     factory = module.get<EmailDriverFactory>(EmailDriverFactory);
     twentyConfigService = module.get<TwentyConfigService>(TwentyConfigService);
+    configGroupHashService = module.get<ConfigGroupHashService>(
+      ConfigGroupHashService,
+    );
 
     jest.clearAllMocks();
   });
@@ -44,7 +56,7 @@ describe('EmailDriverFactory', () => {
     it('should return smtp config key for smtp driver', () => {
       jest.spyOn(twentyConfigService, 'get').mockReturnValue(EmailDriver.SMTP);
       jest
-        .spyOn(factory as any, 'getConfigGroupHash')
+        .spyOn(configGroupHashService, 'computeHash')
         .mockReturnValue('smtp-hash-123');
 
       const result = factory['buildConfigKey']();
@@ -179,7 +191,7 @@ describe('EmailDriverFactory', () => {
           }
         });
       jest
-        .spyOn(factory as any, 'getConfigGroupHash')
+        .spyOn(configGroupHashService, 'computeHash')
         .mockReturnValue('smtp-hash-123');
 
       const driver2 = factory.getCurrentDriver();
@@ -214,7 +226,7 @@ describe('EmailDriverFactory', () => {
         });
 
       jest
-        .spyOn(factory as any, 'getConfigGroupHash')
+        .spyOn(configGroupHashService, 'computeHash')
         .mockReturnValue('smtp-hash-123');
 
       jest.spyOn(factory as any, 'createDriver').mockImplementation(() => {

packages/twenty-server/src/engine/core-modules/email/email-driver.factory.ts

@@ -7,12 +7,16 @@ import { SmtpDriver } from 'src/engine/core-modules/email/drivers/smtp.driver';
 import { EmailDriver } from 'src/engine/core-modules/email/enums/email-driver.enum';
 import { DriverFactoryBase } from 'src/engine/core-modules/twenty-config/dynamic-factory.base';
 import { ConfigVariablesGroup } from 'src/engine/core-modules/twenty-config/enums/config-variables-group.enum';
+import { ConfigGroupHashService } from 'src/engine/core-modules/twenty-config/services/config-group-hash.service';
 import { TwentyConfigService } from 'src/engine/core-modules/twenty-config/twenty-config.service';
 
 @Injectable()
 export class EmailDriverFactory extends DriverFactoryBase<EmailDriverInterface> {
-  constructor(twentyConfigService: TwentyConfigService) {
-    super(twentyConfigService);
+  constructor(
+    twentyConfigService: TwentyConfigService,
+    configGroupHashService: ConfigGroupHashService,
+  ) {
+    super(twentyConfigService, configGroupHashService);
   }
 
   protected buildConfigKey(): string {
@@ -23,7 +27,7 @@ export class EmailDriverFactory extends DriverFactoryBase<EmailDriverInterface>
     }
 
     if (driver === EmailDriver.SMTP) {
-      const emailConfigHash = this.getConfigGroupHash(
+      const emailConfigHash = this.configGroupHashService.computeHash(
         ConfigVariablesGroup.EMAIL_SETTINGS,
       );