feat(#1): Set up monorepo scaffold with pnpm workspaces + TurboRepo

Implements the foundational project structure including:
- pnpm workspaces configuration
- TurboRepo for build orchestration
- NestJS 11.1.12 API (apps/api)
- Next.js 16.1.6 web app (apps/web)
- Shared packages (config, shared, ui)
- TypeScript strict mode configuration
- ESLint + Prettier setup
- Vitest for unit testing (19 passing tests)

Fixes #1

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/api/src/main.ts

@@ -0,0 +1,17 @@
+import { NestFactory } from "@nestjs/core";
+import { AppModule } from "./app.module";
+
+async function bootstrap() {
+  const app = await NestFactory.create(AppModule);
+  app.enableCors();
+
+  const port = process.env["PORT"] ?? 3001;
+  await app.listen(port);
+
+  console.log(`API running on http://localhost:${port}`);
+}
+
+bootstrap().catch((err: unknown) => {
+  console.error("Failed to start application:", err);
+  process.exit(1);
+});