Fix public page layouts and avatar display

🎨 Layout improvements:
- Add full implementations for timeline, masonry, and magazine layouts
- Replace layout stubs with proper React components matching dashboard
- Add timeline with alternating left/right positioning and central line
- Implement masonry layout with dynamic column sizing
- Create magazine layout with featured first item and image previews

🐛 Avatar & URL fixes:
- Fix avatar URL protocol (http → https) in normalize_file_url
- Add http://links.shareon.kr to internal URLs replacement list
- Update get_backend_url to use HTTPS and proper domain from env vars
- Fix CustomizationPanel API URL consistency in DashboardClient

✨ Visual enhancements:
- Proper hover states and transitions for all layout types
- Timeline dots with theme color coordination
- Magazine layout with responsive image handling
- Masonry cards with dynamic content sizing
- Consistent group/link styling across all layouts

🔧 Technical:
- Environment-driven URL generation for production
- Consistent API endpoint usage across components
- Better responsive design for mobile devices
- Improved accessibility with proper alt text and ARIA labels

backend/backend/utils.py

@@ -7,12 +7,14 @@ from django.conf import settings
 
 def get_backend_url():
     """Получить базовый URL backend из настроек"""
-    return getattr(settings, 'BACKEND_URL', 'http://localhost:8000')
+    protocol = os.getenv('DJANGO_BACKEND_PROTOCOL', 'https')
+    domain = os.getenv('DJANGO_BACKEND_DOMAIN', 'links.shareon.kr')
+    return f"{protocol}://{domain}"
 
 
 def get_media_base_url():
     """Получить базовый URL для медиа файлов"""
-    return getattr(settings, 'MEDIA_BASE_URL', 'http://localhost:8000')
+    return get_backend_url()  # Используем тот же базовый URL
 
 
 def build_absolute_url(path):
@@ -48,7 +50,8 @@ def normalize_file_url(file_url):
         'http://web:8000',
         'http://links-web-1:8000', 
         'http://backend:8000',
-        'http://localhost:8000'
+        'http://localhost:8000',
+        'http://links.shareon.kr'  # Заменяем HTTP на HTTPS
     ]
     
     # Заменяем все внутренние URL на внешний