fix(pi): validate user-entry conversation forks

scripts/run-pi-subagent-packaged-smoke.mjs

@@ -164,6 +164,16 @@ function assertProxyProof(proof) {
     || proof?.firstConversation?.parentResponseProjected !== true
     || proof?.firstConversation?.definiteRejectionObserved !== true
     || proof?.firstConversation?.retryAccepted !== true
+    || proof?.fork?.conversationCount !== 2
+    || proof?.fork?.sameAgent !== true
+    || proof?.fork?.targetBindingEstablished !== true
+    || proof?.fork?.distinctSessionBinding !== true
+    || proof?.fork?.workerStatus !== 'ready'
+    || proof?.fork?.runStatus !== 'idle'
+    || proof?.fork?.sourceEntryRole !== 'user'
+    || proof?.fork?.targetHydratedBeforeSourceEntry !== true
+    || proof?.fork?.sourceUnchanged !== true
+    || proof?.fork?.promptReplayObserved !== false
     || proof?.providerCompatibility?.developerRoleRequests !== 0
     || proof?.providerCompatibility?.controlledDefiniteRejections !== 1
     || proof?.currentHostTokenUsedBy?.join(',') !== 'parent,child'
@@ -460,6 +470,43 @@ export async function runPackagedProductProof(options) {
     }
     if (!await composer.isEnabled()) throw new Error('Packaged proxy composer is not editable after the turn');
 
+    const settledProxy = await evaluateProof(electronApplication, 'proxy.status');
+    if (settledProxy?.proxy?.conversationCount !== 1
+      || settledProxy?.proxy?.activeProviderRequests?.parent !== 0
+      || settledProxy?.proxy?.activeProviderRequests?.child !== 0) {
+      throw new Error(`Packaged proxy source did not settle before fork: ${JSON.stringify(settledProxy?.proxy)}`);
+    }
+    const timeline = page.getByTestId('coding-conversation-timeline');
+    const forkActions = timeline.getByRole('button', { name: '从这里创建新对话分支' });
+    await forkActions.waitFor({ state: 'visible', timeout: 30_000 });
+    if (await forkActions.count() !== 1) {
+      throw new Error(`Packaged proxy timeline exposed ${await forkActions.count()} fork actions for one user and one assistant entry`);
+    }
+    const sourceHeader = await page.getByTestId('coding-conversation-header').innerText();
+    await forkActions.click({ timeout: 30_000 });
+    await page.waitForFunction((previous) => {
+      const header = document.querySelector('[data-testid="coding-conversation-header"]');
+      return Boolean(header?.textContent?.includes('(fork)') && header.textContent !== previous);
+    }, sourceHeader, { timeout: 30_000 });
+    const forkedHeader = await page.getByTestId('coding-conversation-header').innerText();
+    const forkedTitle = forkedHeader.split('\n', 1)[0]?.trim();
+    if (!forkedTitle?.includes('(fork)')) {
+      throw new Error(`Packaged proxy fork target was not selected: ${forkedHeader}`);
+    }
+    const agentConversations = page.getByRole('group', { name: 'Packaged proxy proof agent 的对话' });
+    await agentConversations.getByRole('button', { name: forkedTitle, exact: true })
+      .waitFor({ state: 'visible', timeout: 30_000 });
+    const forkedBody = await page.locator('body').innerText();
+    if (forkedBody.includes('本地编程运行时暂时不可用')
+      || forkedBody.includes('正在重新连接本地 Agent')) {
+      throw new Error(`Packaged user-entry fork exposed a runtime banner: ${forkedBody}`);
+    }
+    if (await timeline.getByText(retryPrompt, { exact: true }).count() !== 0
+      || await timeline.getByText('REAL_PARENT_COMPLETE', { exact: true }).count() !== 0
+      || await timeline.getByRole('button', { name: '从这里创建新对话分支' }).count() !== 0) {
+      throw new Error('Packaged fork target did not hydrate at the path before the selected user entry');
+    }
+
     const proxyFinish = await evaluateProof(electronApplication, 'proxy.finish');
     proxyActive = false;
     assertPackagedMain(proxyFinish);
@@ -653,6 +700,12 @@ export async function runPackagedProductProof(options) {
           submissionErrorSafe,
           retryAfterEditEnabled,
           retrySubmitted: true,
+          assistantForkActionHidden: true,
+          userForkActionAvailable: true,
+          forkTargetSelected: true,
+          sameAgentOwnership: true,
+          sourceUnchanged: proxyFinish.proxy?.fork?.sourceUnchanged === true,
+          uncertainPromptReplayed: proxyFinish.proxy?.fork?.promptReplayObserved === true,
           runtimeUnavailableBanner: false,
           permanentRecovering: false,
         },