feat: comprehensive INFO/WARN/ERROR logging across all controller modules

Add structured operational logging at INFO, WARN, and ERROR levels to
every controller module. Standardize custom prefixes ([GEO], [SCHED],
[SYNC]) to use [INFO/WARN/ERROR] [module] format. Fix misleveled logs
(WARN->ERROR for data loss scenarios, WARN->INFO for routine operations).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

controller/internal/web/auth.go

@@ -88,6 +88,7 @@ func (s *Server) RequireAuth(next http.Handler) http.Handler {
 				s.logger.Printf("[DEBUG] [web] auth: rejected %s %s from %s (%s)", r.Method, r.URL.Path, r.RemoteAddr, reason)
 			}
 			if strings.HasPrefix(r.URL.Path, "/api/") {
+				s.logger.Printf("[WARN] [api] Unauthorized request to %s from %s", r.URL.Path, r.RemoteAddr)
 				w.Header().Set("Content-Type", "application/json")
 				w.WriteHeader(http.StatusUnauthorized)
 				fmt.Fprint(w, `{"ok":false,"error":"authentication required"}`)
@@ -203,6 +204,7 @@ func (s *Server) handleLogout(w http.ResponseWriter, r *http.Request) {
 		delete(s.sessions, cookie.Value)
 		s.sessionsMu.Unlock()
 	}
+	s.logger.Printf("[INFO] [web] User logged out from %s", r.RemoteAddr)
 	http.SetCookie(w, &http.Cookie{Name: sessionCookieName, Value: "", Path: "/", MaxAge: -1})
 	http.Redirect(w, r, "/login", http.StatusFound)
 }
@@ -257,6 +259,7 @@ func (s *Server) invalidateAllSessions() {
 	count := len(s.sessions)
 	s.sessions = make(map[string]*session)
 	s.sessionsMu.Unlock()
+	s.logger.Printf("[INFO] [web] All sessions invalidated (cleared %d)", count)
 	if s.isDebug() {
 		s.logger.Printf("[DEBUG] [web] invalidated all sessions (cleared %d)", count)
 	}
@@ -281,6 +284,9 @@ func (s *Server) cleanupSessions() {
 			}
 			remaining := len(s.sessions)
 			s.sessionsMu.Unlock()
+			if expired > 0 {
+				s.logger.Printf("[INFO] [web] Cleaned up %d expired sessions, %d remaining", expired, remaining)
+			}
 			if s.isDebug() && expired > 0 {
 				s.logger.Printf("[DEBUG] [web] session cleanup: expired=%d remaining=%d", expired, remaining)
 			}

controller/internal/web/handler_export.go

@@ -109,6 +109,7 @@ func (s *Server) apiExportEstimate(w http.ResponseWriter, r *http.Request) {
 
 	est, err := s.appExporter.EstimateExport(stackName, drive)
 	if err != nil {
+		s.logger.Printf("[ERROR] [web] Export estimate failed for %s: %v", stackName, err)
 		s.logger.Printf("[DEBUG] [handler_export] apiExportEstimate error: %v", err)
 		jsonError(w, err.Error(), http.StatusInternalServerError)
 		return
@@ -162,6 +163,7 @@ func (s *Server) apiExportStart(w http.ResponseWriter, r *http.Request) {
 		StopApp:   req.StopApp,
 	})
 	if err != nil {
+		s.logger.Printf("[ERROR] [web] Export start failed for %s: %v", req.StackName, err)
 		s.logger.Printf("[DEBUG] [handler_export] apiExportStart error: %v", err)
 		jsonError(w, err.Error(), http.StatusConflict)
 		return
@@ -306,6 +308,7 @@ func (s *Server) apiImportStart(w http.ResponseWriter, r *http.Request) {
 		Password: req.Password,
 	})
 	if err != nil {
+		s.logger.Printf("[ERROR] [web] Import start failed for %s: %v", req.Path, err)
 		s.logger.Printf("[DEBUG] [handler_export] apiImportStart error: %v", err)
 		jsonError(w, err.Error(), http.StatusConflict)
 		return

controller/internal/web/handler_restore.go

@@ -89,6 +89,7 @@ func (s *Server) apiRestoreAll(w http.ResponseWriter, r *http.Request) {
 		jsonError(w, "restore already in progress", http.StatusConflict)
 		return
 	}
+	s.logger.Printf("[INFO] [web] Restore-all initiated from %s", r.RemoteAddr)
 	go s.executeAllRestores()
 
 	jsonResponse(w, map[string]interface{}{

controller/internal/web/handlers.go

@@ -1568,6 +1568,7 @@ func (s *Server) settingsStorageDefaultHandler(w http.ResponseWriter, r *http.Re
 		http.Redirect(w, r, "/settings", http.StatusFound)
 		return
 	}
+	s.logger.Printf("[INFO] [web] Default storage path set to %s", path)
 	http.Redirect(w, r, "/settings?storage_msg=success&storage_detail="+url.QueryEscape("Alapértelmezett adattároló beállítva: "+path), http.StatusFound)
 }
 
@@ -1585,6 +1586,7 @@ func (s *Server) settingsStorageSchedulableHandler(w http.ResponseWriter, r *htt
 		http.Redirect(w, r, "/settings", http.StatusFound)
 		return
 	}
+	s.logger.Printf("[INFO] [web] Storage schedulable updated: %s → %v", path, schedulable)
 	http.Redirect(w, r, "/settings?storage_msg=success&storage_detail="+url.QueryEscape("Adattároló állapot módosítva: "+path), http.StatusFound)
 }
 

controller/internal/web/server.go

@@ -345,6 +345,7 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		}
 		s.debugPageHandler(w, r)
 	default:
+		s.logger.Printf("[WARN] [web] 404 Not Found: %s %s", r.Method, path)
 		http.NotFound(w, r)
 	}
 }

controller/internal/web/storage_handlers.go

@@ -1222,6 +1222,7 @@ func (s *Server) storageDisconnectHandler(w http.ResponseWriter, r *http.Request
 		return
 	}
 
+	s.logger.Printf("[INFO] [web] Disk disconnect completed: %s (stopped %d stacks)", req.Path, len(stoppedStacks))
 	if s.isDebug() {
 		s.logger.Printf("[DEBUG] [web] storageDisconnect: path=%s success, stopped %d stacks", req.Path, len(stoppedStacks))
 	}
@@ -1264,6 +1265,7 @@ func (s *Server) storageReconnectHandler(w http.ResponseWriter, r *http.Request)
 		return
 	}
 
+	s.logger.Printf("[INFO] [web] Disk reconnect completed: %s", req.Path)
 	if s.isDebug() {
 		s.logger.Printf("[DEBUG] [web] storageReconnect: path=%s success, previously stopped stacks=%v", req.Path, stoppedStacks)
 	}
@@ -1309,6 +1311,7 @@ func (s *Server) storageRestartAppsHandler(w http.ResponseWriter, r *http.Reques
 	}
 
 	started, failed := s.storageWatchdog.RestartStoppedApps(req.Path)
+	s.logger.Printf("[INFO] [web] Restart apps for %s: started=%d failed=%d", req.Path, len(started), len(failed))
 	if s.isDebug() {
 		s.logger.Printf("[DEBUG] [web] storageRestartApps: path=%s started=%v failed=%v", req.Path, started, failed)
 	}