fix(browser): preserve chat focus during agent browsing

electron/agent-browser/module.ts

@@ -615,7 +615,7 @@ export class AgentBrowserModule {
   }
 
   async readEvents(input: AgentBrowserReadEventsInput): Promise<AgentBrowserCdpEventPage> {
-    let record = this.requirePresented(input.projectPath);
+    let record = this.requireViewport(input.projectPath);
     const after = normalizeNonNegativeInteger(input.after, 0, 'after');
     const limit = normalizeIntegerRange(input.limit, 100, 1, 200, 'limit');
     const waitMs = normalizeIntegerRange(input.waitMs, 0, 0, MAX_WAIT_MS, 'waitMs');
@@ -645,13 +645,13 @@ export class AgentBrowserModule {
         || current !== record
         || current.eventBuffer.cursor !== cursorBeforeWait;
     });
-    record = this.requirePresented(input.projectPath);
+    record = this.requireViewport(input.projectPath);
     page = record.eventBuffer.read(page.nextCursor, input.methods, limit);
     return page;
   }
 
   async readPayload(input: AgentBrowserReadPayloadInput): Promise<AgentBrowserPayloadChunk> {
-    this.requirePresented(input.projectPath);
+    this.requireViewport(input.projectPath);
     return this.payloadStore.read(input.handle, input.offset, input.maxBytes);
   }
 
@@ -1589,7 +1589,7 @@ export class AgentBrowserModule {
   }
 
   private requireAttached(projectPath: string): BrowserRecord {
-    const record = this.requirePresented(projectPath);
+    const record = this.requireViewport(projectPath);
     if (record.state === 'suspended_devtools') {
       throw new AgentBrowserFault(
         'DEVTOOLS_CONFLICT',
@@ -1617,12 +1617,14 @@ export class AgentBrowserModule {
     return record;
   }
 
-  private requirePresented(projectPath: string): BrowserRecord {
+  private requireViewport(projectPath: string): BrowserRecord {
     const record = this.requireRecord(projectPath);
-    if (!record.visible || !record.bounds) {
+    // Switching to chat hides the native view without ending its debugging session.
+    // A new view still needs its first real viewport before tools can operate.
+    if (!record.bounds) {
       throw new AgentBrowserFault(
         'VIEWPORT_NOT_READY',
-        '开发浏览器已收起，智能体调试已暂停。',
+        '开发浏览器显示区域尚未准备好。',
         true,
         record.generation,
       );