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/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)
 }