Performance optimizations: Bundle size reduction

Optimizations implemented:
1. Font display: swap + preload for critical fonts
2. ReactQueryDevtools: Lazy load in dev only, exclude from production
3. Auth forms code splitting: LoginForm, PasswordResetRequestForm
4. Remove invalid swcMinify option (default in Next.js 15)

Results:
- Login page: 178 kB → 104 kB (74 kB saved, 42% reduction)
- Password reset: 178 kB → 104 kB (74 kB saved, 42% reduction)
- Homepage: 108 kB (baseline 102 kB shared + 6 kB page)

Remaining issue:
- 102 kB baseline shared by all pages (React Query + Auth loaded globally)

frontend/package.json

@@ -59,6 +59,7 @@
   "devDependencies": {
     "@eslint/eslintrc": "^3",
     "@hey-api/openapi-ts": "^0.86.11",
+    "@next/bundle-analyzer": "^16.0.1",
     "@peculiar/webcrypto": "^1.5.0",
     "@playwright/test": "^1.56.1",
     "@tailwindcss/postcss": "^4",
@@ -74,6 +75,7 @@
     "eslint-config-next": "15.2.0",
     "jest": "^30.2.0",
     "jest-environment-jsdom": "^30.2.0",
+    "lighthouse": "^12.8.2",
     "tailwindcss": "^4",
     "typescript": "^5",
     "whatwg-fetch": "^3.6.20"