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 <[email protected]>

frontend/src/services/email.service.ts

@@ -35,41 +35,41 @@ export interface EmailPreview {
 export const emailService = {
   // Get email configuration
   async getConfig(): Promise<EmailConfig> {
-    const response = await api.get<EmailConfig>('/api/admin/email/config');
+    const response = await api.get<EmailConfig>('/admin/email/config');
     return response.data;
   },
 
   // Update email configuration
   async updateConfig(config: EmailConfig): Promise<void> {
-    await api.post('/api/admin/email/config', config);
+    await api.post('/admin/email/config', config);
   },
 
   // Test email configuration
   async testEmail(testEmail: string): Promise<void> {
-    await api.post('/api/admin/email/test', { test_email: testEmail });
+    await api.post('/admin/email/test', { test_email: testEmail });
   },
 
   // Get all email templates
   async getTemplates(): Promise<EmailTemplate[]> {
-    const response = await api.get<EmailTemplate[]>('/api/admin/email/templates');
+    const response = await api.get<EmailTemplate[]>('/admin/email/templates');
     return response.data;
   },
 
   // Get single template
   async getTemplate(key: string): Promise<EmailTemplate> {
-    const response = await api.get<EmailTemplate>(`/api/admin/email/templates/${key}`);
+    const response = await api.get<EmailTemplate>(`/admin/email/templates/${key}`);
     return response.data;
   },
 
   // Update email template
   async updateTemplate(key: string, template: Partial<EmailTemplate>): Promise<void> {
-    await api.put(`/api/admin/email/templates/${key}`, template);
+    await api.put(`/admin/email/templates/${key}`, template);
   },
 
   // Preview email template
   async previewTemplate(key: string, previewData: Record<string, string>, language: 'en' | 'de' = 'en'): Promise<EmailPreview> {
     const response = await api.post<EmailPreview>(
-      `/api/admin/email/templates/${key}/preview`,
+      `/admin/email/templates/${key}/preview`,
       { preview_data: previewData, language }
     );
     return response.data;