feat: enhance security logging and ensure rate limit blocks are properly tracked

- Add comprehensive logging for rate limit blocks with full request details
  - IP address (with proper proxy detection), user agent, headers, timestamps
  - Rate limit info (current count, limit, remaining, reset time)
  - Separate tracking for auth vs general endpoints

- Enhance authentication failure logging
  - JWT validation failures with detailed error info
  - Admin auth attempts without token
  - Failed token validation with user context
  - All events include IP, path, method, user agent

- Improve Winston logger configuration for production
  - Add automatic log rotation (10MB errors, 50MB combined)
  - Create separate security.log for auth/rate limit events
  - Ensure logs directory exists automatically
  - Add structured JSON format for log aggregation
  - Support container logging with LOG_TO_CONSOLE env var

- Create comprehensive documentation
  - Security logging guide with examples
  - Monitoring recommendations
  - Configuration reference

- Add test script to verify logging functionality

All rate limit settings remain configurable via admin panel:
- Window duration, max requests, auth limits
- Skip authenticated requests option
- Public endpoints only option

🤖 Generated with [Claude Code](https://claude.ai/code)

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

frontend/src/App.tsx

@@ -23,6 +23,7 @@ import {
   SettingsPage,
   CMSPage
 } from './pages/admin';
+import { CMSPageEnhanced } from './pages/admin/CMSPageEnhanced';
 import { AdminLayout, AdminAuthWrapper } from './components/admin';
 import { PageErrorBoundary, OfflineIndicator, SkipLink, DynamicFavicon } from './components/common';
 import { MaintenanceWrapper } from './components/MaintenanceWrapper';
@@ -109,7 +110,7 @@ function App() {
                       <Route path="analytics" element={<AnalyticsPage />} />
                       <Route path="branding" element={<BrandingPage />} />
                       <Route path="settings" element={<SettingsPage />} />
-                      <Route path="cms" element={<CMSPage />} />
+                      <Route path="cms" element={<CMSPageEnhanced />} />
                       <Route index element={<Navigate to="/admin/dashboard" replace />} />
                     </Route>
                   </Route>