fix(web): settle orphan inflight bubbles via shared cancel helper

Wire cancelInflightAssistantMessages on stop so composer unlock and
message status stay consistent across sessions.

web/src/App.tsx

@@ -12,7 +12,6 @@ import {
 import { mapApiMembersToProjectMembers } from './lib/projectMemberAdapter';
 import { resolveCurrentDocRole } from './lib/currentDocRole';
 import {
-  COMPOSER_INFLIGHT_STATUSES,
   resolveChatComposerStreaming,
 } from './lib/chatComposerStreaming';
 import {
@@ -1215,7 +1214,7 @@ export default function App() {
     applyControlledInvalidationPlan,
   });
 
-  // 用户主动停止：仅中止当前 session 的活跃 turn，并结算仍挂在 inflight 的孤儿气泡。
+  // 用户主动停止：中止当前 session 活跃 turn，并结算仍挂在 inflight 的孤儿气泡。
   const handleStopStreaming = () => {
     turnRuntime.abortActiveSessionTurns();
     taskRunStream.abortSession(activeSessionId);
@@ -1224,14 +1223,7 @@ export default function App() {
       void cancelTaskRun(runId).catch(() => undefined);
       taskRunStream.setRunId(activeSessionId, null);
     }
-    const inflight = COMPOSER_INFLIGHT_STATUSES as readonly string[];
-    setMessages((prev) =>
-      prev.map((m) =>
-        m.role === 'assistant' && m.status && inflight.includes(m.status)
-          ? { ...m, status: 'cancelled' as const }
-          : m,
-      ),
-    );
+    setMessages((prev) => cancelInflightAssistantMessages(prev, activeSessionId));
   };
 
   const handleLogout = () => {

web/src/lib/squadCompletionObservation.test.ts

@@ -1,6 +1,9 @@
 import { describe, it } from 'node:test';
 import assert from 'node:assert/strict';
-import { reduceSquadObservation } from './squadCompletionObservation';
+import {
+  cancelInflightAssistantMessages,
+  reduceSquadObservation,
+} from './squadCompletionObservation';
 
 const turn = {
   userPromptMatched: true,
@@ -59,4 +62,26 @@ describe('squadCompletionObservation', () => {
     assert.equal(verdict.action, 'wait');
     assert.equal(verdict.sawInflight, true);
   });
+
+  it('cancelInflightAssistantMessages settles only this-session assistant inflight', () => {
+    const next = cancelInflightAssistantMessages(
+      [
+        {
+          sessionId: 's1',
+          role: 'assistant',
+          status: 'streaming_status',
+          livePhaseLabel: '任务执行中…',
+        },
+        { sessionId: 's1', role: 'user', status: 'completed' },
+        { sessionId: 's2', role: 'assistant', status: 'streaming_status' },
+        { sessionId: 's1', role: 'assistant', status: 'completed' },
+      ],
+      's1',
+    );
+    assert.equal(next[0].status, 'cancelled');
+    assert.equal(next[0].livePhaseLabel, undefined);
+    assert.equal(next[1].status, 'completed');
+    assert.equal(next[2].status, 'streaming_status');
+    assert.equal(next[3].status, 'completed');
+  });
 });

web/src/lib/squadCompletionObservation.ts

@@ -30,6 +30,38 @@ export function isInflightChatStatus(status: string): boolean {
   return (INFLIGHT_CHAT_STATUSES as readonly string[]).includes(status);
 }
 
+type InflightCancelableMessage = {
+  sessionId?: string;
+  role: string;
+  status: string;
+  livePhaseLabel?: string;
+};
+
+/**
+ * Stop/abort alone can leave assistant bubbles in pending/streaming_status,
+ * which keeps InputArea locked on "停止当前生成". Mark those as cancelled so
+ * the composer returns to send-ready without page.evaluate.
+ */
+export function cancelInflightAssistantMessages<T extends InflightCancelableMessage>(
+  messages: T[],
+  sessionId: string,
+): T[] {
+  return messages.map((message) => {
+    if (
+      message.sessionId === sessionId &&
+      message.role === 'assistant' &&
+      isInflightChatStatus(message.status)
+    ) {
+      return {
+        ...message,
+        status: 'cancelled',
+        livePhaseLabel: undefined,
+      };
+    }
+    return message;
+  });
+}
+
 export function isSuccessTerminalChatStatus(status: string): boolean {
   return (SUCCESS_TERMINAL_CHAT_STATUSES as readonly string[]).includes(status);
 }