fix(node): keep client/inbound edits working when a node is offline (#4923, #4931)

Node-backed client and inbound edits no longer hard-fail when the backing node is offline or disabled. Edits commit to the panel DB immediately and reconcile to the node when it reconnects (eventual consistency); the panel is the single source of truth for desired config.

- Add Node.ConfigDirty/ConfigDirtyAt; mark a node dirty when an edit commits without reaching it (cleared via CAS on ConfigDirtyAt after a full reconcile).
- nodePushPlan() reads node state fresh from the DB, skips the push for offline/disabled nodes (no 10s hang), and treats push failures as non-fatal across every mutation path (client add/update/del + bulk + attach/detach; inbound add/update/del/toggle/resetTraffic).
- ReconcileNode() pushes the panel's desired config to a node on reconnect (refreshing the remote tag cache first) and prunes node-side orphans; runs before the traffic pull in the node sync job.
- While a node is dirty the traffic pull applies only up/down deltas and node-initiated disables, never overwriting desired config from a stale node snapshot.
- Surface a non-blocking 'saved; will sync on reconnect' warning to the UI.

Validated with a two-panel Docker E2E: client delete/update, attach/detach, and inbound add/delete all reconcile correctly offline -> reconnect.

frontend/src/utils/index.ts

@@ -1,5 +1,6 @@
 import axios from 'axios';
 import type { AxiosError, AxiosRequestConfig, AxiosResponse } from 'axios';
+import i18next from 'i18next';
 import { getMessage } from './messageBus';
 
 type RespEnvelope = { success?: unknown; msg?: unknown; obj?: unknown };
@@ -32,6 +33,14 @@ export class HttpUtil {
     }
     const messageType = msg.success ? 'success' : 'error';
     getMessage()[messageType](msg.msg);
+    if (
+      msg.success &&
+      msg.obj &&
+      typeof msg.obj === 'object' &&
+      (msg.obj as { nodePending?: unknown }).nodePending === true
+    ) {
+      getMessage().warning(i18next.t('pages.inbounds.toasts.savedNodeOfflineWillSync'));
+    }
   }
 
   static _respToMsg(resp: AxiosResponse | undefined): Msg {