fix: resolve frontend API routing issues for Traefik deployment

Major fixes for production deployment with Traefik:

1. API Path Fixes:
   - Remove double /api prefix from all frontend service calls
   - Fix auth.service.ts to use correct paths (/auth/admin/login)
   - Update all services to use single /api prefix from base URL
   - Fix template literal paths in photo services

2. Docker Configuration:
   - Add build args for VITE_API_URL in docker-compose.prod.yml
   - Create Dockerfile.prod with proper API URL configuration
   - Ensure frontend is built with correct API base path

3. Documentation:
   - Add comprehensive TRAEFIK_DEPLOYMENT.md guide
   - Document proper Traefik labels and routing configuration
   - Include troubleshooting steps for common issues
   - Explain network configuration and SSL handling

This resolves:
- 502 Bad Gateway errors
- Double /api/api paths in requests
- Frontend unable to communicate with backend
- Login functionality not working

The frontend now correctly calls the backend API through Traefik's
routing, with all requests going to /api/* being forwarded to the
backend service on port 3000.

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

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

frontend/src/pages/GalleryPage.tsx

@@ -33,7 +33,7 @@ export const GalleryPage: React.FC = () => {
   const { data: settingsData } = useQuery({
     queryKey: ['gallery-settings'],
     queryFn: async () => {
-      const response = await api.get('/api/public/settings');
+      const response = await api.get('/public/settings');
       return response.data;
     },
     staleTime: 5 * 60 * 1000, // Cache for 5 minutes

frontend/src/pages/admin/AdminLoginPage.tsx

@@ -27,7 +27,7 @@ export const AdminLoginPage: React.FC = () => {
   const { data: settingsData } = useQuery({
     queryKey: ['admin-login-settings'],
     queryFn: async () => {
-      const response = await api.get('/api/public/settings');
+      const response = await api.get('/public/settings');
       return response.data;
     },
     staleTime: 5 * 60 * 1000, // Cache for 5 minutes

frontend/src/pages/public/LegalPage.tsx

@@ -21,7 +21,7 @@ export const LegalPage: React.FC = () => {
   const { data: settingsData } = useQuery({
     queryKey: ['public-settings'],
     queryFn: async () => {
-      const response = await api.get('/api/public/settings');
+      const response = await api.get('/public/settings');
       return response.data;
     },
     staleTime: 5 * 60 * 1000, // Cache for 5 minutes