Feature: Automated configuration backups with scheduling

- Create/Download/Upload/Restore database backups (PostgreSQL and SQLite)
- Configurable data directory backups (via settings.py)
- Scheduled backups (daily/weekly) via Celery Beat
- Retention policy (keep last N backups)
- Token-based auth for async task polling
- X-Accel-Redirect support for nginx file serving
- Comprehensive tests

apps/api/urls.py

@@ -27,6 +27,7 @@ urlpatterns = [
     path('core/', include(('core.api_urls', 'core'), namespace='core')),
     path('plugins/', include(('apps.plugins.api_urls', 'plugins'), namespace='plugins')),
     path('vod/', include(('apps.vod.api_urls', 'vod'), namespace='vod')),
+    path('backups/', include(('apps.backups.api_urls', 'backups'), namespace='backups')),
     # path('output/', include(('apps.output.api_urls', 'output'), namespace='output')),
     #path('player/', include(('apps.player.api_urls', 'player'), namespace='player')),
     #path('settings/', include(('apps.settings.api_urls', 'settings'), namespace='settings')),