Production-ready improvements: security hardening, Redis sessions, retry logic, updated pricing

Changes:
- Removed hardcoded admin credentials (now requires env vars)
- Added Redis session storage with in-memory fallback
- Improved CORS configuration with warnings for development mode
- Added retry_with_backoff decorator for translation API calls
- Updated pricing: Starter=, Pro=, Business=
- Stripe price IDs now loaded from environment variables
- Added redis to requirements.txt
- Updated .env.example with all new configuration options
- Created COMPREHENSIVE_REVIEW_AND_PLAN.md with deployment roadmap
- Frontend: Updated pricing page, new UI components

frontend/package.json

@@ -26,6 +26,7 @@
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
     "framer-motion": "^12.23.24",
+    "lightningcss-win32-x64-msvc": "^1.30.2",
     "lucide-react": "^0.555.0",
     "next": "16.0.6",
     "react": "19.2.0",
@@ -41,6 +42,7 @@
     "@types/react-dom": "^19",
     "eslint": "^9",
     "eslint-config-next": "16.0.6",
+    "lightningcss": "^1.30.2",
     "tailwindcss": "^4",
     "tw-animate-css": "^1.4.0",
     "typescript": "^5"