fix: unify i18n service discovery and handler resolution logic

- Make getDiscoveryInfo() async using resolveService() fallback chain
- Populate locale from actual i18n service instead of hardcoded values
- Update all framework adapters and plugins to await getDiscoveryInfo()
- Add discovery-handler consistency tests
- Update CHANGELOG.md

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

CHANGELOG.md

@@ -7,6 +7,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+- **i18n service registration & state inconsistency** — Discovery API (`getDiscoveryInfo`) now uses
+  the same async `resolveService()` fallback chain that request handlers (`handleI18n`) use, ensuring
+  the reported service status is always consistent with actual runtime availability.
+- Discovery `locale` field is now populated from the actual i18n service (`getDefaultLocale`,
+  `getLocales`) instead of being hardcoded, so clients get accurate locale information.
+- Updated all framework adapters (Hono, Express, Fastify, Next.js, NestJS, Nuxt, SvelteKit),
+  the dispatcher plugin, and the MSW plugin to `await` the now-async `getDiscoveryInfo()`.
+
 ### Changed
 - Updated ROADMAP.md for v3.0 release preparation with full codebase scan results
 - Audited all @deprecated items: 14 in spec, 9 in runtime packages (23 total)

packages/adapters/express/src/index.ts

@@ -71,8 +71,8 @@ export function createExpressRouter(options: ExpressAdapterOptions): Router {
   };
 
   // --- Discovery ---
-  router.get('/', (_req: Request, res: Response) => {
-    res.json({ data: dispatcher.getDiscoveryInfo(prefix) });
+  router.get('/', async (_req: Request, res: Response) => {
+    res.json({ data: await dispatcher.getDiscoveryInfo(prefix) });
   });
 
   // --- Auth ---

packages/adapters/fastify/src/index.ts

@@ -70,7 +70,7 @@ export async function objectStackPlugin(fastify: FastifyInstance, options: Fasti
 
   // --- Discovery ---
   fastify.get(`${prefix}`, async (_request: FastifyRequest, reply: FastifyReply) => {
-    return reply.send({ data: dispatcher.getDiscoveryInfo(prefix) });
+    return reply.send({ data: await dispatcher.getDiscoveryInfo(prefix) });
   });
 
   // --- .well-known ---

packages/adapters/hono/src/index.ts

@@ -72,8 +72,8 @@ export function createHonoApp(options: ObjectStackHonoOptions): Hono {
   };
 
   // --- Discovery ---
-  app.get(`${prefix}`, (c) => {
-    return c.json({ data: dispatcher.getDiscoveryInfo(prefix) });
+  app.get(`${prefix}`, async (c) => {
+    return c.json({ data: await dispatcher.getDiscoveryInfo(prefix) });
   });
 
   // --- .well-known ---

packages/adapters/nestjs/src/__mocks__/runtime.ts

@@ -2,7 +2,7 @@
 import { vi } from 'vitest';
 
 export class HttpDispatcher {
-  getDiscoveryInfo = vi.fn().mockReturnValue({ version: '1.0' });
+  getDiscoveryInfo = vi.fn().mockResolvedValue({ version: '1.0' });
   handleGraphQL = vi.fn().mockResolvedValue({ data: {} });
   handleAuth = vi.fn().mockResolvedValue({ handled: true, response: { status: 200, body: { ok: true } } });
   handleMetadata = vi.fn().mockResolvedValue({ handled: true, response: { status: 200, body: [] } });

packages/adapters/nestjs/src/index.ts

@@ -95,8 +95,8 @@ export class ObjectStackController {
 
   // --- Discovery Endpoint ---
   @Get()
-  discovery() {
-    return { data: this.service.dispatcher.getDiscoveryInfo('/api') };
+  async discovery() {
+    return { data: await this.service.dispatcher.getDiscoveryInfo('/api') };
   }
 
   @Post('graphql')

packages/adapters/nestjs/src/nestjs.test.ts

@@ -136,8 +136,8 @@ describe('ObjectStackController', () => {
   });
 
   describe('discovery()', () => {
-    it('returns discovery info from the dispatcher', () => {
-      const result = controller.discovery();
+    it('returns discovery info from the dispatcher', async () => {
+      const result = await controller.discovery();
       expect(result).toEqual({ data: { version: '1.0' } });
       expect(service.dispatcher.getDiscoveryInfo).toHaveBeenCalledWith('/api');
     });

packages/adapters/nextjs/src/index.ts

@@ -60,7 +60,7 @@ export function createRouteHandler(options: NextAdapterOptions) {
 
     // --- 0. Discovery Endpoint ---
     if (segments.length === 0 && method === 'GET') {
-      return NextResponse.json({ data: dispatcher.getDiscoveryInfo(options.prefix || '/api') });
+      return NextResponse.json({ data: await dispatcher.getDiscoveryInfo(options.prefix || '/api') });
     }
 
     try {

packages/adapters/nuxt/src/index.ts

@@ -82,8 +82,8 @@ export function createH3Router(options: NuxtAdapterOptions): Router {
   // --- Discovery ---
   router.get(
     `${prefix}`,
-    defineEventHandler(() => {
-      return { data: dispatcher.getDiscoveryInfo(prefix) };
+    defineEventHandler(async () => {
+      return { data: await dispatcher.getDiscoveryInfo(prefix) };
     }),
   );
 

packages/adapters/sveltekit/src/index.ts

@@ -97,7 +97,7 @@ export function createRequestHandler(options: SvelteKitAdapterOptions) {
 
     // --- Discovery ---
     if (segments.length === 0 && method === 'GET') {
-      return new Response(JSON.stringify({ data: dispatcher.getDiscoveryInfo(prefix) }), {
+      return new Response(JSON.stringify({ data: await dispatcher.getDiscoveryInfo(prefix) }), {
         status: 200,
         headers: { 'Content-Type': 'application/json' },
       });