feat: local dev setup with SSR fix and one-command dev script

- Add Next.js instrumentation.ts to polyfill Node.js v25+ broken localStorage
- Add dev-setup.sh for one-command local development setup
- Disable Supabase analytics in config.toml (avoids slow logflare image pull)
- Switch backend dev script to tsx watch for better DX

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

website-monitoring-backend/package.json

@@ -7,7 +7,7 @@
   "scripts": {
     "build": "tsc",
     "start": "node dist/index.js",
-    "dev": "tsc --watch",
+    "dev": "tsx watch src/index.ts",
     "test": "NODE_OPTIONS='--experimental-vm-modules' jest --passWithNoTests",
     "test:coverage": "NODE_OPTIONS='--experimental-vm-modules' jest --coverage",
     "lint": "eslint src/",
@@ -50,6 +50,7 @@
     "jest": "^30.2.0",
     "prettier": "^3.8.1",
     "supertest": "^7.2.2",
-    "ts-jest": "^29.4.6"
+    "ts-jest": "^29.4.6",
+    "tsx": "^4.21.0"
   }
 }