auto-claude: subtask-5-1 - E2E verification documentation and middleware fix

Created comprehensive E2E verification framework:
- E2E_VERIFICATION.md: Complete manual testing guide with 9 scenarios
- scripts/verify-e2e-rate-limiting.sh: Automated API testing script
- scripts/test-concurrent-rate-limit.sh: Concurrent request testing
- scripts/reset-rate-limit.sh: Database reset utility for testing
- SUBTASK_5-1_VERIFICATION_REPORT.md: Status and blocker documentation

Fixed middleware configuration:
- Updated src/middleware.ts matcher to exclude /api/ routes
- Changed from complex negative lookahead to explicit locale matching
- Pattern now: ['/', '/(de|en|sr)/:path*']

Known issue:
- Middleware fix requires dev server restart to take effect
- API routes currently return 404 until server is restarted
- All implementation code is complete and ready for testing

Test coverage:
- Basic rate limiting flow (5 requests succeed, 6th fails)
- Response header verification (X-RateLimit-Remaining, Retry-After)
- Persistence testing (across page refreshes, browser sessions)
- Multi-locale support (en, de, sr)
- Error handling and validation
- Concurrent request handling
- Database record verification

Next steps:
1. Restart dev server: npm run dev
2. Run automated tests: bash ./scripts/verify-e2e-rate-limiting.sh
3. Perform manual browser testing per E2E_VERIFICATION.md
4. Verify database records in Supabase
5. Mark subtask as completed

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/middleware.ts

@@ -11,6 +11,5 @@ export const config = {
   matcher: [
     '/',
     '/(de|en|sr)/:path*',
-    '/((?!api|_next|_vercel|.*\\..*).*)',
   ],
 };