feat(desktop): push publish tasks via AMQP topic dispatch WebSocket

Introduce a desktop.task.dispatch topic exchange with per-client routing
keys. Tenant-api publishes a task_available frame keyed by target client
ID when a publish job is created; every instance binds its own transient
queue and forwards to the matching WebSocket (/api/desktop/dispatch) it
owns. Desktop-client now prefers this push channel and only falls back
to HTTP /lease polling when the socket is down. Also drop admin-web
monitoring-plugin remnants and scope the publish modal account list to
publish platforms.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/desktop-client/src/main/runtime-controller.ts

@@ -89,6 +89,7 @@ import {
   upsertDesktopAccount,
 } from "./transport/api-client";
 import { SseClient, SseClientError } from "./transport/sse-client";
+import { DispatchWsClient } from "./transport/dispatch-ws-client";
 
 type RuntimeTone = "info" | "success" | "warn" | "danger";
 type RuntimeTaskStatus =
@@ -184,6 +185,8 @@ interface RuntimeState {
   heartbeatTimer: ReturnType<typeof setInterval> | null;
   pullTimer: ReturnType<typeof setInterval> | null;
   sseClient: SseClient | null;
+  dispatchWsClient: DispatchWsClient | null;
+  dispatchWsConnected: boolean;
   lastHeartbeatAt: number;
   lastHeartbeatStatus: "idle" | "success" | "failed";
   lastPullAt: number;
@@ -210,6 +213,8 @@ const state: RuntimeState = {
   heartbeatTimer: null,
   pullTimer: null,
   sseClient: null,
+  dispatchWsClient: null,
+  dispatchWsConnected: false,
   lastHeartbeatAt: 0,
   lastHeartbeatStatus: "idle",
   lastPullAt: 0,
@@ -354,6 +359,7 @@ function startRuntime(): void {
   recordActivity("success", "调度节点已启动", "已启动 SSE、心跳上报和兜底拉取。");
 
   connectEventStream();
+  connectDispatchWs();
   scheduleHeartbeatLoop();
   schedulePullLoop();
 
@@ -383,6 +389,11 @@ function stopRuntime(): void {
     state.sseClient.stop();
     state.sseClient = null;
   }
+  if (state.dispatchWsClient) {
+    state.dispatchWsClient.stop();
+    state.dispatchWsClient = null;
+  }
+  state.dispatchWsConnected = false;
 
   setTransportSseState("idle");
   setSchedulerPhase("idle");
@@ -521,6 +532,63 @@ function connectEventStream(): void {
   sseClient.start();
 }
 
+function connectDispatchWs(): void {
+  if (!canRunLive(state.session)) {
+    return;
+  }
+
+  state.dispatchWsClient?.stop();
+
+  const wsUrl = buildApiUrl(state.session.api_base_url, "/api/desktop/dispatch")
+    .replace(/^http:\/\//, "ws://")
+    .replace(/^https:\/\//, "wss://");
+
+  const client = new DispatchWsClient({
+    url: wsUrl,
+    headers: {
+      Authorization: `Bearer ${state.session.client_token}`,
+    },
+  });
+
+  client.on("open", () => {
+    state.dispatchWsConnected = true;
+    setSchedulerError(null);
+    recordActivity("success", "任务分发通道已连接", "AMQP 直推 WebSocket 已就绪,发布任务将以低延迟到达。");
+  });
+
+  client.on("connected", () => {
+    state.dispatchWsConnected = true;
+  });
+
+  client.on("task_available", (payload) => {
+    if (!isDesktopTaskEvent(payload)) {
+      return;
+    }
+    state.dispatchWsConnected = true;
+    handleTaskEvent(payload);
+  });
+
+  client.on("error", (payload) => {
+    state.dispatchWsConnected = false;
+    const message = errorMessage(payload);
+    recordActivity("warn", "任务分发通道异常", message);
+  });
+
+  client.on("close", () => {
+    state.dispatchWsConnected = false;
+  });
+
+  client.on("reconnect", (payload) => {
+    if (!isReconnectPayload(payload)) {
+      return;
+    }
+    recordActivity("info", "任务分发通道退避等待", `将在 ${payload.delayMs}ms 后重连 WebSocket。`);
+  });
+
+  state.dispatchWsClient = client;
+  client.start();
+}
+
 function handleTaskEvent(event: DesktopTaskEventMessage): void {
   const existing = state.tasks.get(event.task_id);
   const next: RuntimeTaskRecord = {
@@ -871,11 +939,18 @@ function pumpExecutionLoop(): void {
   }
 
   if (state.activeExecutions.size === 0) {
-    void pullNextTask("publish");
+    // Publish task_available is push-delivered over the dispatch WebSocket. We
+    // only fall back to the HTTP pull when the push channel is down, otherwise
+    // every scheduler tick would wake the /lease endpoint for no reason.
+    if (!state.dispatchWsConnected) {
+      void pullNextTask("publish");
+    }
     return;
   }
 
   if (canStartAnotherMonitorExecution()) {
+    // Monitor has not been migrated to the dispatch channel yet, so it still
+    // relies on the periodic pull as its primary signal.
     void pullNextTask("monitor");
   }
 }