refactor: remove standalone proxies, add Traefik provider with Docker labels

Standalone proxy removal:
- Delete store, API handlers, proxy manager, health monitor, validator, hints
- Delete frontend pages (proxies list, create, edit) and components (ProxyCard, ProxyForm, ProxyFilter, ProxyGroup, ValidationChecklist)
- Remove proxy routes from router, nav items, dashboard references
- Clean up SystemHealthCard to remove proxy section

Traefik provider:
- Add TraefikProvider implementing proxy.Provider via Docker labels
- ContainerLabels() returns traefik.enable, router rule, entrypoints, service port, TLS cert resolver, docker network
- ConfigureRoute() returns router name (labels handle routing at container creation)
- DeleteRoute() is no-op (container removal auto-deregisters)
- Ping() checks Traefik API health (optional)
- Wire ContainerLabels into deployer (executeDeploy + blueGreenDeploy)
- Add Traefik settings: entrypoint, cert_resolver, network, api_url
- Add traefik option to proxy provider selector in settings UI
- Show conditional Traefik config fields
- Add i18n keys (EN + RU)

internal/api/router.go

@@ -21,7 +21,7 @@ import (
 )
 
 // DNSProviderChangedFunc is called when DNS settings change so the caller can
-// update the provider on the deployer and proxy manager.
+// update the provider on the deployer.
 type DNSProviderChangedFunc func(provider dns.Provider)
 
 // Server holds all dependencies for the API layer.
@@ -37,7 +37,6 @@ type Server struct {
 	localAuth    *auth.LocalAuth
 	oidcProvider *auth.OIDCProvider
 	staleScanner *stale.Scanner
-	proxyManager *proxy.Manager
 
 	dnsProviderMu        sync.RWMutex
 	dnsProvider          dns.Provider
@@ -89,12 +88,6 @@ func (s *Server) SetStaleScanner(scanner *stale.Scanner) {
 	s.staleScanner = scanner
 }
 
-// SetProxyManager sets the proxy manager on the server.
-// Called after both the API server and proxy manager are initialized.
-func (s *Server) SetProxyManager(pm *proxy.Manager) {
-	s.proxyManager = pm
-}
-
 // SetBackupEngine sets the backup engine on the server.
 func (s *Server) SetBackupEngine(engine *backup.Engine) {
 	s.backupEngine = engine
@@ -261,19 +254,6 @@ func (s *Server) Router() chi.Router {
 			// Stale container endpoints (read).
 			r.Get("/containers/stale", s.listStaleContainers)
 
-			// Proxy endpoints (read-only for any authenticated user).
-			r.Get("/proxies", s.listProxies)
-			r.Get("/proxies/all", s.listAllProxies)
-			r.Route("/proxies/{id}", func(r chi.Router) {
-				r.Get("/", s.getProxy)
-				// Admin-only proxy mutations.
-				r.Group(func(r chi.Router) {
-					r.Use(auth.AdminOnly)
-					r.Put("/", s.updateProxy)
-					r.Delete("/", s.deleteProxy)
-				})
-			})
-
 			// Admin-only routes: require admin role.
 			r.Group(func(r chi.Router) {
 				r.Use(auth.AdminOnly)
@@ -300,10 +280,6 @@ func (s *Server) Router() chi.Router {
 				// Registry creation.
 				r.Post("/registries", s.createRegistry)
 
-				// Proxy mutation endpoints.
-				r.Post("/proxies/validate", s.validateProxy)
-				r.Post("/proxies", s.createProxy)
-
 				// Stale container cleanup endpoints.
 				// Bulk route must be registered before parameterized route.
 				r.Post("/containers/stale/cleanup", s.bulkCleanupStaleContainers)