feat: Monitor groups and chart information

web/lib/api.ts

@@ -62,6 +62,8 @@ export interface MonitorState {
 export interface Monitor {
     monitor_id: string;
     name: string;
+    /** Display-only heading on the monitors page. Empty means ungrouped. */
+    group?: string;
     type: MonitorType;
     target: MonitorTarget;
     interval_sec: number;
@@ -75,6 +77,7 @@ export interface Monitor {
 
 export interface MonitorInput {
     name: string;
+    group?: string;
     type: MonitorType;
     target: MonitorTarget;
     interval_sec: number;