feat: 对接设计 Agent Gateway WebSocket

需求：服务端统一 Agent Gateway 将设计任务状态流切换为 WebSocket，客户端需要实时展示生成任务并支持断线恢复。

实现：Electron Main 管理 Session、一次性 Ticket、WebSocket 心跳与游标续传，按关闭码回收会话；Renderer 继续通过本机 Host API 的 SSE 投影接收任务事件，并保留 REST 降级同步。

验证：typecheck、变更文件 ESLint、37 个聚焦测试及 build:vite 通过。

electron/main/index.ts

@@ -32,6 +32,10 @@ import { logger } from '../utils/logger';
 import { warmupNetworkOptimization } from '../utils/uv-env';
 import { resolvePythonRuntime } from '../utils/python-runtime';
 import { initTelemetry } from '../utils/telemetry';
+import {
+  getOrCreateAgentGatewaySessionClientId,
+  rotateAgentGatewaySessionClientId,
+} from '../utils/store';
 
 import { isQuitting, setQuitting } from './app-state';
 import { applyProxySettings } from './proxy';
@@ -73,6 +77,7 @@ import {
   LocalImageWorkspace,
 } from '../image-workspace/local-workspace';
 import { WorksSquareDesignWorkspace } from '../image-workspace/works-square-workspace';
+import type { DesignWorkspaceModule } from '../image-workspace/module';
 
 const WINDOWS_APP_USER_MODEL_ID = 'app.niancode.desktop';
 const isE2EMode = process.env.NIANCODE_E2E === '1';
@@ -152,6 +157,7 @@ let hostApiServer: Server | null = null;
 let projectProgressSync: ReturnType<typeof createProjectProgressSync> | null = null;
 let worksCloudDeployment: ReturnType<typeof createWorksCloudDeployment> | null = null;
 let agentBrowser: AgentBrowserModule | null = null;
+let imageWorkspaceModule: DesignWorkspaceModule | null = null;
 const mainWindowFocusState = createMainWindowFocusState();
 const quitLifecycleState = createQuitLifecycleState();
 const launchDeepLinkUrl = findNianCodeDeepLinkUrl(process.argv);
@@ -419,7 +425,13 @@ async function initialize(): Promise<void> {
   });
   const imageWorkspace = localImageWorkspaceEnabled
     ? new LocalImageWorkspace({ userDataDir: app.getPath('userData') })
-    : new WorksSquareDesignWorkspace();
+    : new WorksSquareDesignWorkspace({
+        eventSessionClientIdStore: {
+          getOrCreate: getOrCreateAgentGatewaySessionClientId,
+          rotate: rotateAgentGatewaySessionClientId,
+        },
+      });
+  imageWorkspaceModule = imageWorkspace;
   if (localImageWorkspaceEnabled) {
     logger.info('AI painting workspace is using local development storage');
   } else {
@@ -647,9 +659,13 @@ if (gotTheLock) {
     const stopAgentBrowserPromise = agentBrowser?.dispose().catch((err) => {
       logger.warn('agentBrowser.dispose() error during quit:', err);
     }) ?? Promise.resolve();
+    const closeImageWorkspacePromise = imageWorkspaceModule?.closeEventSessions?.().catch((err) => {
+        logger.warn('imageWorkspace.closeEventSessions() error during quit:', err);
+      }) ?? Promise.resolve();
     const stopPromise = Promise.allSettled([
       stopOpencodePromise,
       stopAgentBrowserPromise,
+      closeImageWorkspacePromise,
     ]);
     const timeoutPromise = new Promise<'timeout'>((resolve) => {
       setTimeout(() => resolve('timeout'), 5000);