refactor: migrate to monorepo structure with Docker, PocketBase, and e2e tests

- Reorganize into apps/, packages/, docs/, e2e/, pocketbase/ directories
- Add Dockerfiles for web, worker, and PocketBase services
- Add docker-compose.yml for local orchestration
- Add turbo.json for monorepo task management
- Add Playwright e2e test infrastructure
- Add PocketBase backend with migrations
- Remove Vite/Next.js/ESLint/PostCSS config files
- Update package.json with workspace dependencies
- Add .env.example and .dockerignore

apps/web/app/api/health/route.ts

@@ -0,0 +1,9 @@
+import { NextResponse } from 'next/server';
+
+export async function GET() {
+  return NextResponse.json({
+    status: 'ok',
+    timestamp: new Date().toISOString(),
+    version: process.env.npm_package_version || '0.1.0',
+  });
+}