v2.0.0: Complete rewrite — React + Express + PostgreSQL + Docker

BREAKING: Full rewrite from static HTML to production-grade stack.

Features:
- React 18 + Vite + Tailwind CSS (mobile-first)
- Express + Prisma + PostgreSQL backend
- JWT authentication with role-based access
- Weekly Mon-Sun timesheets with auto-save
- Multiple homeowner entries per day
- Submit → Approve/Reject workflow
- Server-side PDF generation
- SMTP email integration
- Admin panel with reporting & filters
- Dark mode (system-aware)
- Docker Compose one-command deploy
- Non-root containers, Helmet, bcrypt, Zod validation

frontend/postcss.config.js

@@ -0,0 +1,6 @@
+export default {
+  plugins: {
+    tailwindcss: {},
+    autoprefixer: {},
+  },
+};