feat: auto-discover container images from registries

- Add ListImages() to registry interface, implement for Gitea
- Add owner field to registry config (needed for Gitea packages API)
- GET /api/registries/:id/images endpoint
- "Browse Images" button on Projects and Quick Deploy pages
- Image dropdown with registry grouping and search
- i18n support (EN/RU) for all new UI strings

internal/api/router.go

@@ -171,6 +171,7 @@ func (s *Server) Router() chi.Router {
 				r.Delete("/", s.deleteRegistry)
 				r.Post("/test", s.testRegistry)
 				r.Get("/tags/*", s.listRegistryTags)
+				r.Get("/images", s.listRegistryImages)
 			})
 
 			// Settings endpoints.