feat: scaffold monorepo with Turborepo + NestJS + Next.js

- Turborepo monorepo with pnpm workspaces
- apps/api: NestJS 11.x with CQRS module
- apps/web: Next.js 14 App Router + TailwindCSS
- src/modules/shared: base entities, Result pattern, value objects
- TypeScript 5.7+ strict mode, shared tsconfig base
- Build pipeline: dev, build, lint, test, typecheck

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/api/src/app.controller.ts

@@ -0,0 +1,9 @@
+import { Controller, Get } from '@nestjs/common';
+
+@Controller()
+export class AppController {
+  @Get()
+  healthCheck() {
+    return { status: 'ok', service: 'goodgo-api' };
+  }
+}