perf: add rate limiting, validation, logging, and error handling

- Add express-rate-limit with tiered rate limits per endpoint
- Add express-validator for input validation on all API routes
- Add winston + morgan for structured logging
- Add node-cache for lottery result caching (5min TTL, 1000 max keys)
- Convert OCR to async task queue with max 2 concurrent jobs
- Add global error handler middleware
- Add React ErrorBoundary for client-side error handling
- Fix memory leaks in OCR task queue and lottery cache
- Add per-item error handling in batch ticket updates
- Fix SQL UPDATE to include user_id in WHERE clause

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/package.json

@@ -15,6 +15,11 @@
     "multer": "^1.4.5-lts.1",
     "tesseract.js": "^5.0.4",
     "axios": "^1.6.7",
-    "cheerio": "^1.0.0-rc.12"
+    "cheerio": "^1.0.0-rc.12",
+    "express-rate-limit": "^7.1.5",
+    "express-validator": "^7.0.1",
+    "node-cache": "^5.1.2",
+    "winston": "^3.11.0",
+    "morgan": "^1.10.0"
   }
 }