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/generated/types.ts

@@ -322,6 +322,8 @@ export interface Node {
   apiToken: string;
   basePath: string;
   clientCount: number;
+  configDirty: boolean;
+  configDirtyAt: number;
   cpuPct: number;
   createdAt: number;
   depletedCount: number;

frontend/src/generated/zod.ts

@@ -339,6 +339,8 @@ export const NodeSchema = z.object({
   apiToken: z.string(),
   basePath: z.string(),
   clientCount: z.number().int(),
+  configDirty: z.boolean(),
+  configDirtyAt: z.number().int(),
   cpuPct: z.number(),
   createdAt: z.number().int(),
   depletedCount: z.number().int(),