feat: migrate backend foundation to NestJS

apps/api/src/nest/domain-route.service.ts

@@ -0,0 +1,16 @@
+import type { FastifyReply, FastifyRequest } from 'fastify';
+import type { Handler } from '../core/http.js';
+import { RequestContextFactory } from './request-context.factory.js';
+
+export abstract class DomainRouteService {
+  protected constructor(
+    protected readonly contextFactory: RequestContextFactory,
+    private readonly handlers: Record<string, Handler>,
+  ) {}
+
+  execute(name: string, request: FastifyRequest, reply: FastifyReply) {
+    const handler = this.handlers[name];
+    if (!handler) throw new Error(`Missing domain route handler: ${name}`);
+    return handler(this.contextFactory.create(request, reply));
+  }
+}