fix(ui): reconcile completed chat sends

Fixes #87699.\n\nRoutes ACK-completed Control UI chat sends through the existing run lifecycle reconciliation path so stale selected-session rows cannot re-enable the composer/Stop state after the conversation has already completed.\n\nVerification: focused UI/unit tests, Control UI E2E chat-flow test, autoreview clean, Testbox changed gate tbx_01kt68xvz17fcnmd3wj6f7pk6f, and PR CI run 26872484363 green after failed-job rerun for transient runner setup failures.

ui/src/ui/app-chat.test.ts

@@ -10,6 +10,7 @@ import {
   resetChatAttachmentPayloadStoreForTest,
 } from "./chat/attachment-payload-store.ts";
 import type { executeSlashCommand } from "./chat/slash-command-executor.ts";
+import { loadSessions } from "./controllers/sessions.ts";
 import type { GatewaySessionRow, SessionsListResult } from "./types.ts";
 
 type ExecuteSlashCommand = typeof executeSlashCommand;
@@ -2116,6 +2117,43 @@ describe("handleSendChat", () => {
     expect(userMessage.role).toBe("user");
   });
 
+  it("keeps ACK-completed sends idle when sessions.list returns a stale active row", async () => {
+    const request = vi.fn(async (method: string, params?: unknown) => {
+      if (method === "chat.send") {
+        const payload = requireRecord(params, "chat send payload");
+        return { runId: payload.idempotencyKey, status: "ok" };
+      }
+      if (method === "chat.history") {
+        return { messages: [] };
+      }
+      if (method === "sessions.list") {
+        return createSessionsResult([
+          row("agent:main", { hasActiveRun: true, status: "running", startedAt: 1 }),
+        ]);
+      }
+      throw new Error(`Unexpected request: ${method}`);
+    });
+    const host = makeHost({
+      client: { request } as unknown as ChatHost["client"],
+      chatMessage: "already done",
+      sessionsResult: createSessionsResult([
+        row("agent:main", { hasActiveRun: true, status: "running", startedAt: 1 }),
+      ]),
+    });
+
+    await handleSendChat(host);
+    await Promise.resolve();
+    await loadSessions(host as unknown as Parameters<typeof loadSessions>[0]);
+
+    expect(host.chatRunId).toBeNull();
+    expect(host.chatStream).toBeNull();
+    expect(hasAbortableSessionRun(host)).toBe(false);
+    expect(host.sessionsResult?.sessions[0]).toMatchObject({
+      hasActiveRun: false,
+      status: "done",
+    });
+  });
+
   it("keeps delayed chat.send ACK effects scoped to the submitted session", async () => {
     const sent = createDeferred<unknown>();
     const request = vi.fn((method: string) => {

ui/src/ui/app-chat.ts

@@ -928,6 +928,7 @@ async function sendQueuedChatMessage(
         reconcileChatRunLifecycle(
           host as unknown as Parameters<typeof reconcileChatRunLifecycle>[0],
           {
+            outcome: "done",
             sessionStatus: "done",
             runId: ack.runId,
             sessionKey,
@@ -935,7 +936,8 @@ async function sendQueuedChatMessage(
             clearChatStream: true,
             clearToolStream: true,
             clearSideResultTerminalRuns: true,
-            clearRunStatus: true,
+            publishRunStatus: false,
+            armLocalTerminalReconcile: true,
           },
         );
         void loadChatHistory(host as unknown as ChatState);

ui/src/ui/controllers/chat.test.ts

@@ -1538,6 +1538,20 @@ describe("sendChatMessage", () => {
     expect(state.chatRunId).toBeNull();
     expect(state.chatStream).toBeNull();
     expect(state.chatStreamStartedAt).toBeNull();
+    const runState = state as ChatState & {
+      chatRunStatus?: unknown;
+      lastLocalTerminalReconcile?: unknown;
+    };
+    expect(runState.chatRunStatus).toMatchObject({
+      phase: "done",
+      runId: "gateway-complete-run",
+      sessionKey: "main",
+    });
+    expect(runState.lastLocalTerminalReconcile).toMatchObject({
+      phase: "done",
+      runId: "gateway-complete-run",
+      sessionKey: "main",
+    });
   });
 
   it("serializes non-image chat attachments as files", async () => {

ui/src/ui/controllers/chat.ts

@@ -949,9 +949,18 @@ export async function sendChatMessage(
   try {
     const ack = await requestChatSend(state, { message: msg, attachments, runId });
     if (ack.status === "ok") {
-      state.chatRunId = null;
-      state.chatStream = null;
-      state.chatStreamStartedAt = null;
+      reconcileChatRunLifecycle(
+        state as unknown as Parameters<typeof reconcileChatRunLifecycle>[0],
+        {
+          outcome: "done",
+          sessionStatus: "done",
+          runId: ack.runId,
+          sessionKey: state.sessionKey,
+          clearLocalRun: true,
+          clearChatStream: true,
+          armLocalTerminalReconcile: true,
+        },
+      );
     } else {
       state.chatRunId = ack.runId;
     }