diff --git a/docs/复刻待办清单-2026-10-17.md b/docs/复刻待办清单-2026-10-17.md
index 826d56c..ca9ead6 100644
--- a/docs/复刻待办清单-2026-10-17.md
+++ b/docs/复刻待办清单-2026-10-17.md
@@ -220,12 +220,41 @@
 
 ### 08. 新建任务发送后的立即切页与占位
 
-- [ ] 盘点发送到创建会话、准备环境、接收首个事件之间的阻塞位置。
-- [ ] 对照原版发送后的页面切换时机与等待状态。
-- [ ] 发送后立即进入消息页面并显示用户消息；启动较慢时显示合适的助手占位/准备状态。
-- [ ] 验收：慢启动、正常启动、发送失败、停止、切换任务；不等到模型输出后才切页，不重复创建会话或丢失草稿。
+- [x] 盘点发送到创建会话、准备环境、接收首个事件之间的阻塞位置。
+- [x] 对照原版发送后的页面切换时机与等待状态。
+- [x] 发送后立即进入消息页面并显示用户消息；启动较慢时显示合适的助手占位/准备状态。
+- [x] 验收：慢启动、正常启动、发送失败、停止、切换任务；不等到模型输出后才切页，不重复创建会话或丢失草稿。
 
-状态：待 REA 对照与发送状态链路排查。
+状态：已实现并通过真实窗口回归（发送即切页 + 乐观用户消息 + 启动占位 + 真实回合替换 + 失败/停止/切换任务）。
+
+阻塞位置盘点（YCode 现状）：
+- 渲染进程 `stores/chat.ts` 的 `send()` 在无会话时依次 `await session.create` → `await chat.send`，旧实现只有两步都完成后才把用户消息与助手占位写入 `messages`，因此「点了发送什么也不动」直到回合就绪。
+- 主进程 `chat:send` 在返回前要完成：附件/上下文准备、`createCapabilitySnapshot`、`getOmpKernel`（运行环境启动，本轮实测约 1.9–2.3 s）、`sessions.startTurn`；模型回合本身在后台推进，不属于返回前的阻塞。
+
+原版证据：
+- 启动阶段文案：REA `ev_717fa5e846e64d67ac19c8925d121bff632c0d3aefb3603b10858559cabb2dcb`（WorkBuddy 5.8.2，`contexts-BMeWSUHk.js`，SHA-256 `5f35b7489b107e21ef452c8ee88a95265756f6fc444841eef869228bbc44768b`）：`chat.prepare.<stage>` 表与显示逻辑见 `docs/对话启动提示文案-2026-10-16.md`——阶段文案渲染在流式状态栏主文案位置，进入终态/失败/非 idle/MCP 进度后隐藏，其余回落「思考中」。本次占位使用 `acquiring_runtime` =「正在启动对话运行环境…」（用户确认沿用 5.8.2 已有内容，不重新采集）。
+- REA 采集限制（已核到实现层）：visual probe 的 `text` 动作要求 enabled text/search `INPUT`，`key` 动作对可编辑内容上的 Enter/Space 直接拒绝（`.tmp/rea-css-runtime/dist/browser/CdpElectronVisualProbe.js`；schema `.tmp/rea-css-runtime/dist/domain/javascript/ElectronVisualProbeSchema.js`）。WorkBuddy 新建任务编辑器是 `DIV[role=textbox]._editable_1cxd2_1`，因此无法用 REA 驱动发送并抓取「发送后」逐帧等待态；本项不通过其它通道查看/驱动原版。三次采集（`ev_a492a83d…`、`ev_150e8217…`、`ev_5b13ec7d…`）与限制说明见 `.tmp/todo08-wb-new-task/notes.md`。
+- 观察范围：桌面端浅色主题、本机 5.8.3 运行时（文案表来自 5.8.2 已回收证据）。未覆盖：原版发送后逐帧顺序与各段时长。
+
+实现：
+- `stores/chat.ts`：无会话发送时先落地乐观的「用户消息 + 助手占位」（`local-user-*` / `local-assistant-*`，占位带 `prepareStage: acquiring_runtime` 与 `turnStartedAt`），随后才 `await session.create` / `chat.send`；`newSession(context, seedMessages)` 允许把乐观消息带进新会话；真实结果到达时先过滤 `local-*` 再追加真实用户消息与占位，避免重复；失败时移除乐观消息并写入 `error`。
+- `components/ChatPane.tsx`：`submit()` 在发送前清空输入框，失败时把草稿恢复到当前所有者键（会话创建后草稿已迁移到会话 id）；消息非空即离开首页布局（`isHome = currentId === null || messages.length === 0`）。
+- `workbuddy/conversation/prepare-phases.ts`（新增）与 `StreamingFooter` 的 `prepareText`：按回收的 `chat.prepare` 表渲染「正在启动对话运行环境…」替换「思考中」，真实回合一到位即自动回落。
+- `shared/types.ts`：`ChatMessage.prepareStage`（仅渲染进程启动占位使用，不持久化）。
+
+验证：新增 `scripts/verify-new-task-switch.cjs`（真实隔离 Electron + 真实 preload/IPC/渲染进程 + 真实 OMP + 受控本地上游）30 项断言全 PASS：
+- 计时（点击发送为 t0）：对话页、用户消息、启动占位、「已处理」计时均在 **+26 ms** 出现；启动占位在 **+1.9 s** 让位给真实回合，真实回复在 **+2.6 s** 渲染（另一次跑分 +23.8 ms / +2.27 s / +2.97 s）——占位确实覆盖了运行环境启动窗口。
+- 不重复：一次发送只创建 1 个会话；回合结束后 `.cr-self-bubble` 恰好 1 条（无乐观+真实重复）；占位在真实回合出现前清除。
+- 发送失败（清空模型注册表后发送）：草稿恢复为原文、无残留乐观消息、错误「请先添加并选择自定义模型」显示、回到新建页、无启动占位。
+- 停止与切换任务：回合运行中切到新任务再切回，消息与运行状态都在；点击停止后助手消息状态为 `cancelled`、取消指示可见、无残留占位、仍只有 1 条用户消息。
+- 回归：`npm run typecheck`、`npm run build`、`npm run test:chat`、`npm run test:conversation`、`npm run test:conversation-ipc`、`node scripts/verify-user-message-edit.cjs` 全部通过。
+- 报告：`.tmp/new-task-switch-641vdN/report.json`（另有 `.tmp/new-task-switch-TX5VSX/`）。
+
+遗留：
+1. 原版「发送后」逐帧等待态（先后顺序、每段时长）无 REA 运行时证据（探针限制见上），本项只对齐可证部分。
+2. 发送失败时仍会留下一个空会话（`session.create` 已成功、回合未开始）；原版在准备失败时是否保留会话未采集。
+3. 启动阶段目前只使用 `acquiring_runtime` 一条；原版多阶段（expert → … → checking_launch_config）的发出方、顺序与时长未采集，不按字符串表臆造。
+4. 发送窗口内没有「停止」入口（`停止` 只在回合运行后出现，沿用既有实现）；原版在准备阶段是否可直接取消未采集。
 
 ### 09. 账户菜单与页面
 
diff --git a/scripts/rea/probe-new-task-send-20261017.json b/scripts/rea/probe-new-task-send-20261017.json
new file mode 100644
index 0000000..a236ff5
--- /dev/null
+++ b/scripts/rea/probe-new-task-send-20261017.json
@@ -0,0 +1,17 @@
+{
+  "include_fonts": false,
+  "include_message_content": true,
+  "track_selectors": [
+    ".conversation-page-chrome__content",
+    ".conversation-input",
+    ".cr-input-editor-host",
+    ".cr-send-button"
+  ],
+  "actions": [
+    { "kind": "wait", "step_id": "wait-100ms", "duration_ms": 0, "frames": 1 },
+    { "kind": "wait", "step_id": "wait-300ms", "duration_ms": 200, "frames": 1 },
+    { "kind": "wait", "step_id": "wait-500ms", "duration_ms": 100, "frames": 1 },
+    { "kind": "wait", "step_id": "wait-1000ms", "duration_ms": 400, "frames": 1 },
+    { "kind": "wait", "step_id": "wait-2000ms", "duration_ms": 1000, "frames": 1 }
+  ]
+}
diff --git a/scripts/verify-new-task-switch.cjs b/scripts/verify-new-task-switch.cjs
new file mode 100644
index 0000000..5a03fd6
--- /dev/null
+++ b/scripts/verify-new-task-switch.cjs
@@ -0,0 +1,256 @@
+// TODO 08 验收：新任务发送后的立即切页与占位。
+// 真实隔离 YCode（真实 preload/IPC/渲染进程）+ 真实 OMP + 受控本地 OpenAI 兼容上游。
+//
+// 原版依据（REA ev_717fa5e846e64d67ac19c8925d121bff632c0d3aefb3603b10858559cabb2dcb，
+// WorkBuddy 5.8.2，见 docs/对话启动提示文案-2026-10-16.md）：启动阶段文案取自
+// chat.prepare.<stage>，渲染在流式状态栏主文案位置。YCode 侧使用 acquiring_runtime
+// =「正在启动对话运行环境…」作为主进程回合就绪前的占位文案。
+// 原版「发送后」逐帧等待态没有 REA 运行时证据：REA visual probe 的 text 动作只接受
+// INPUT、key 动作排除可编辑内容上的 Enter/Space（见 .tmp/todo08-wb-new-task/notes.md），
+// 因此本脚本只验收可证行为：发送即切页 + 用户消息先出现 + 准备阶段占位先于真实回合 +
+// 真实消息替换不重复 + 发送失败恢复草稿且不残留乐观消息。
+const fs = require('node:fs/promises')
+const path = require('node:path')
+const assert = require('node:assert/strict')
+
+if (!process.versions.electron) {
+  ;(async () => {
+    const directory = await fs.mkdtemp(path.resolve('.tmp/new-task-switch-'))
+    const home = path.join(directory, 'home')
+    await fs.mkdir(home, { recursive: true })
+    const env = { ...process.env, YCODE_USER_DATA_DIR: path.join(directory, 'data'), YCODE_QA_DIRECTORY: directory,
+      YCODE_QA_REAL_OMP: process.env.YCODE_OMP_PATH || path.join(process.env.LOCALAPPDATA || '', 'Ygent', 'omp.exe'),
+      YCODE_OMP_HOME: home, YCODE_DISABLE_GPU: '1', YCODE_QA_OFFSCREEN: '1' }
+    delete env.ELECTRON_RUN_AS_NODE; delete env.ELECTRON_RENDERER_URL
+    const child = require('node:child_process').spawn(require('electron'),
+      ['--no-sandbox', '--disable-gpu-sandbox', __filename], { env, windowsHide: true, stdio: ['ignore', 'pipe', 'pipe'] })
+    let output = ''
+    child.stdout.on('data', bytes => { output += bytes; if (bytes.toString().includes('NEW_TASK_SWITCH_')) process.stdout.write(bytes) })
+    child.stderr.on('data', bytes => { output += bytes })
+    const timer = setTimeout(() => child.kill(), 240000)
+    child.once('exit', async code => {
+      clearTimeout(timer)
+      await fs.writeFile(path.join(directory, 'process.log'), output)
+      console.log(JSON.stringify({ directory, exitCode: code }))
+      if (code) console.error(output.slice(-8000))
+      process.exitCode = code ? 1 : 0
+    })
+  })().catch(error => { console.error(error); process.exitCode = 1 })
+} else {
+  const { app, BrowserWindow } = require('electron')
+  const { createServer } = require('node:http')
+  const { pathToFileURL } = require('node:url')
+  const directory = process.env.YCODE_QA_DIRECTORY
+  app.disableHardwareAcceleration()
+  process.env.YCODE_OMP_PATH = process.env.YCODE_QA_REAL_OMP
+  app.setPath('home', path.join(directory, 'home'))
+  const checks = []
+  const snapshots = {}
+  const rendererErrors = []
+  let main, server, phase = 'boot'
+  const pause = ms => new Promise(resolve => setTimeout(resolve, ms))
+  const read = (source, win = main) => Promise.race([win.webContents.executeJavaScript(source),
+    new Promise((_, reject) => setTimeout(() => reject(Error('Renderer timeout: ' + source.slice(0, 120))), 20000))])
+  async function wait(source, label) {
+    for (let index = 0; index < 400; index++) { const value = await read(source); if (value) return value; await pause(40) }
+    throw Error('Timeout: ' + label)
+  }
+  async function step(label) { phase = label; await fs.writeFile(path.join(directory, 'phase.txt'), label) }
+  function check(label, actual, expected) {
+    const pass = typeof expected === 'function' ? expected(actual) : JSON.stringify(actual) === JSON.stringify(expected)
+    checks.push({ label, pass, actual, expected: typeof expected === 'function' ? expected.toString() : expected })
+  }
+  async function fill(value) {
+    await read(`(()=>{const input=[...document.querySelectorAll('.wb-composer__input')].find(node=>node.offsetParent!==null);
+      if(!input)throw new Error('Missing composer input');
+      Object.getOwnPropertyDescriptor(HTMLTextAreaElement.prototype,'value').set.call(input,${JSON.stringify(value)});
+      input.dispatchEvent(new Event('input',{bubbles:true}));return true})()`)
+  }
+  const within = limit => value => typeof value === 'number' && Number.isFinite(value) && value >= 0 && value < limit
+
+  ;(async () => {
+    // 受控上游：首个响应刻意延迟，保证「真实回合」到达前有一段可观测的占位窗口。
+    server = createServer(async (req, res) => {
+      let raw = ''
+      for await (const part of req) raw += part
+      const body = JSON.parse(raw || '{}')
+      // 「停止验收」场景需要一个更长的回合，方便在运行中切走/切回再停止。
+      await pause(JSON.stringify(body).includes('停止验收') ? 5000 : 600)
+      const content = `LOCAL_REPLY_${body.model}`
+      if (!body.stream) { res.setHeader('content-type', 'application/json'); res.end(JSON.stringify({ choices: [{ message: { role: 'assistant', content } }] })); return }
+      res.writeHead(200, { 'content-type': 'text/event-stream', 'cache-control': 'no-cache' })
+      const chunk = delta => `data: ${JSON.stringify({ id: 'local-test', object: 'chat.completion.chunk', created: 1, model: body.model, choices: [{ index: 0, delta, finish_reason: null }] })}\n\n`
+      res.write(chunk({ role: 'assistant', content }))
+      res.write(`data: ${JSON.stringify({ id: 'local-test', object: 'chat.completion.chunk', created: 1, model: body.model, choices: [{ index: 0, delta: {}, finish_reason: 'stop' }], usage: { prompt_tokens: 20, completion_tokens: 5, total_tokens: 25 } })}\n\ndata: [DONE]\n\n`)
+      res.end()
+    })
+    await new Promise(resolve => server.listen(0, '127.0.0.1', resolve))
+    const baseUrl = `http://127.0.0.1:${server.address().port}/v1`
+
+    await fs.mkdir(process.env.YCODE_USER_DATA_DIR, { recursive: true })
+    app.setPath('userData', process.env.YCODE_USER_DATA_DIR)
+    app.setPath('sessionData', process.env.YCODE_USER_DATA_DIR)
+    await import(pathToFileURL(path.resolve('out/main/index.mjs')).href)
+    await app.whenReady()
+    for (let index = 0; index < 120; index++) {
+      main = BrowserWindow.getAllWindows().find(win => win.getTitle() === 'YCode')
+      if (main && !main.webContents.isLoading()) break
+      await pause(50)
+    }
+    assert.ok(main)
+    main.webContents.on('console-message', (_event, level, message) => { if (level >= 2) rendererErrors.push(message) })
+    await wait('!!window.ycode && !!document.querySelector(".chat-pane")', 'main renderer')
+    await read(`window.ycode.models.save(${JSON.stringify({ id: 'local-one', name: 'Local One', providerId: 'custom',
+      model: 'model-one', baseUrl, apiKey: 'LOCAL_TEST_KEY', supportsToolCall: true, maxInputTokens: 64000, maxOutputTokens: 4096 })})`)
+    await read('window.ycode.models.select("local-one")')
+
+    await step('home-surface')
+    await wait(`!!document.querySelector('.wb-home-composer') && !!document.querySelector('.wb-composer__input')`, 'home composer')
+    const sessionCountBefore = (await read('window.ycode.session.list()')).length
+    check('no session exists before the first send', sessionCountBefore, 0)
+
+    await step('send-new-task')
+    const message = 'QA 新任务发送验收'
+    await read(`(()=>{const marks={};const text=${JSON.stringify(message)};
+      const state=()=>({conversation:!!document.querySelector('.cr-message-list'),
+        user:[...document.querySelectorAll('.cr-self-bubble')].some(node=>node.textContent.includes(text)),
+        prepare:document.body.textContent.includes('正在启动对话运行环境…'),
+        duration:!!document.querySelector('.cr-streaming-duration'),
+        reply:document.body.textContent.includes('LOCAL_REPLY_model-one')});
+      const tick=()=>{const now=performance.now();const value=state();
+        if(!marks.conversation&&value.conversation)marks.conversation=now;
+        if(!marks.userMessage&&value.user)marks.userMessage=now;
+        if(!marks.prepareText&&value.prepare)marks.prepareText=now;
+        if(marks.prepareText&&!marks.prepareCleared&&!value.prepare)marks.prepareCleared=now;
+        if(!marks.duration&&value.duration)marks.duration=now;
+        if(!marks.reply&&value.reply)marks.reply=now;};
+      window.__qa={t0:0,marks};window.__qaTick=tick;
+      const observer=new MutationObserver(tick);observer.observe(document.documentElement,{subtree:true,childList:true,characterData:true});
+      tick();return true})()`)
+    await fill(message)
+    await wait(`(()=>{const button=document.querySelector('button[aria-label="发送"]');return !!button&&!button.disabled})()`, 'send button enabled')
+    await read(`(()=>{window.__qa.t0=performance.now();document.querySelector('button[aria-label="发送"]').click();return true})()`)
+    await wait(`!!(window.__qa.marks.conversation&&window.__qa.marks.userMessage&&window.__qa.marks.prepareText)`, 'optimistic marks')
+    await pause(150)
+    snapshots.optimistic = await read(`(()=>{const input=[...document.querySelectorAll('.wb-composer__input')].find(node=>node.offsetParent!==null);
+      return {t0:window.__qa.t0,marks:{...window.__qa.marks},inputValue:input?input.value:null,
+        userBubbles:[...document.querySelectorAll('.cr-self-bubble')].map(node=>node.textContent.trim()),
+        home:!!document.querySelector('.wb-home-composer'),conversation:!!document.querySelector('.cr-message-list'),
+        prepare:document.body.textContent.includes('正在启动对话运行环境…'),duration:!!document.querySelector('.cr-streaming-duration')}})()`)
+    const marks = snapshots.optimistic.marks
+    const t0 = snapshots.optimistic.t0
+    check('send switches to the conversation view immediately', marks.conversation - t0, within(500))
+    check('user message is visible immediately after send', marks.userMessage - t0, within(500))
+    check('startup placeholder appears immediately after send', marks.prepareText - t0, within(500))
+    check('streaming duration is running during the wait', marks.duration - t0, within(500))
+    check('composer draft is cleared at send time', snapshots.optimistic.inputValue, '')
+    check('home surface is left at send time', snapshots.optimistic.home, false)
+    check('optimistic user message is on screen', snapshots.optimistic.userBubbles.some(text => text.includes(message)), true)
+    check('startup placeholder text is the recovered acquiring_runtime string', snapshots.optimistic.prepare, true)
+
+    await step('real-turn')
+    const sessions = await read('window.ycode.session.list()')
+    const sessionId = sessions[0] && sessions[0].id
+    check('exactly one session was created for the send', sessions.length, 1)
+    const done = await wait(`window.ycode.session.messages(${JSON.stringify(sessionId)}).then(list=>{const last=list.at(-1);return last&&last.status==='done'&&last})`, 'turn finished')
+    check('local upstream answered the turn', done.content, 'LOCAL_REPLY_model-one')
+    await wait(`document.body.textContent.includes('LOCAL_REPLY_model-one')`, 'reply rendered')
+    await pause(250)
+    snapshots.finished = await read(`(()=>({userBubbles:[...document.querySelectorAll('.cr-self-bubble')].map(node=>node.textContent.trim()),
+      prepare:document.body.textContent.includes('正在启动对话运行环境…'),duration:!!document.querySelector('.cr-streaming-duration'),
+      reply:document.body.textContent.includes('LOCAL_REPLY_model-one'),marks:{...window.__qa.marks}}))()`)
+    const finalMarks = snapshots.finished.marks
+    check('startup placeholder is cleared before the reply arrives', finalMarks.prepareCleared !== undefined && finalMarks.prepareCleared <= (finalMarks.reply ?? Number.POSITIVE_INFINITY), true)
+    check('startup placeholder is gone after the turn', snapshots.finished.prepare, false)
+    check('streaming placeholder is replaced by the finished footer', snapshots.finished.duration, false)
+    check('exactly one user message after the turn (no optimistic duplicate)', snapshots.finished.userBubbles.length, 1)
+    check('reply is rendered in the conversation', snapshots.finished.reply, true)
+    check('real turn took longer than the optimistic render (placeholder was needed)', finalMarks.reply - finalMarks.userMessage,
+      value => typeof value === 'number' && value > 300)
+    snapshots.timings = { conversationMs: finalMarks.conversation - t0, userMessageMs: finalMarks.userMessage - t0,
+      prepareTextMs: finalMarks.prepareText - t0, durationMs: finalMarks.duration - t0,
+      prepareClearedMs: finalMarks.prepareCleared === undefined ? null : finalMarks.prepareCleared - t0,
+      replyMs: finalMarks.reply === undefined ? null : finalMarks.reply - t0 }
+
+    await step('send-failure')
+    // 清空模型注册表：发送会在 chat:send 的模型解析阶段被拒绝（早于任何回合/网络请求），
+    // 这是「发送失败」路径；同时避免误连外部网关。
+    const removed = await read(`window.ycode.models.list()`)
+    for (const model of removed.models) await read(`window.ycode.models.remove(${JSON.stringify(model.id)})`)
+    const registryAfterRemoval = await read(`window.ycode.models.list()`)
+    check('model registry is empty for the failure case', registryAfterRemoval.models.length, 0)
+    await read(`document.querySelector('[title="新建任务"]').click()`)
+    await wait(`!!document.querySelector('.wb-home-composer')`, 'home surface after new task')
+    const failureMessage = 'QA 发送失败草稿恢复'
+    await fill(failureMessage)
+    await wait(`(()=>{const button=document.querySelector('button[aria-label="发送"]');return !!button&&!button.disabled})()`, 'send enabled again')
+    await read(`document.querySelector('button[aria-label="发送"]').click()`)
+    // 发送失败的错误可能落在发送框（发送框自身状态）或会话区状态行（store error）；
+    // 首条消息失败时布局会从对话页切回新建页，发送框重挂载，因此两处都接受。
+    await wait(`!!(document.querySelector('.wb-composer__error[role="alert"]')||document.querySelector('.msg__status--error'))`, 'send error surfaced')
+    await pause(250)
+    snapshots.failure = await read(`(()=>{const input=[...document.querySelectorAll('.wb-composer__input')].find(node=>node.offsetParent!==null);
+      const composerError=document.querySelector('.wb-composer__error');const statusError=document.querySelector('.msg__status--error');
+      return {inputValue:input?input.value:null,
+        userBubbles:document.querySelectorAll('.cr-self-bubble').length,
+        composerError:composerError?composerError.textContent:null,statusError:statusError?statusError.textContent:null,
+        prepare:document.body.textContent.includes('正在启动对话运行环境…'),home:!!document.querySelector('.wb-home-composer')}})()`)
+    check('failed send restores the draft text', snapshots.failure.inputValue, failureMessage)
+    check('failed send leaves no optimistic user message', snapshots.failure.userBubbles, 0)
+    check('failed send surfaces an error', snapshots.failure.composerError ?? snapshots.failure.statusError,
+      value => typeof value === 'string' && /模型/.test(value))
+    check('failed send leaves no startup placeholder', snapshots.failure.prepare, false)
+    check('failed send returns to the home surface', snapshots.failure.home, true)
+
+    await step('stop-and-switch')
+    await read(`window.ycode.models.save(${JSON.stringify({ id: 'local-one', name: 'Local One', providerId: 'custom',
+      model: 'model-one', baseUrl, apiKey: 'LOCAL_TEST_KEY', supportsToolCall: true, maxInputTokens: 64000, maxOutputTokens: 4096 })})`)
+    await read('window.ycode.models.select("local-one")')
+    const idsBeforeStopScenario = (await read('window.ycode.session.list()')).map(session => session.id)
+    await read(`document.querySelector('[title="新建任务"]').click()`)
+    await wait(`!!document.querySelector('.wb-home-composer')`, 'home surface for the stop scenario')
+    const stopMessage = 'QA 停止验收'
+    await fill(stopMessage)
+    await wait(`(()=>{const button=document.querySelector('button[aria-label="发送"]');return !!button&&!button.disabled})()`, 'send enabled for the stop scenario')
+    await read(`document.querySelector('button[aria-label="发送"]').click()`)
+    await wait(`document.body.textContent.includes('正在启动对话运行环境…')`, 'startup placeholder for the stop scenario')
+    const stopSessionId = (await read('window.ycode.session.list()')).map(session => session.id)
+      .find(id => !idsBeforeStopScenario.includes(id))
+    check('stop scenario created exactly one new session', typeof stopSessionId === 'string' && !!stopSessionId, true)
+    await wait(`!!document.querySelector('button[aria-label="停止"]')`, 'stop button available while running')
+    // 运行中切到新任务再切回：消息与运行状态不丢。
+    await read(`document.querySelector('[title="新建任务"]').click()`)
+    await wait(`!!document.querySelector('.wb-home-composer') && !document.querySelector('.cr-self-bubble')`, 'switched to a new task mid-turn')
+    await read(`(()=>{const row=[...document.querySelectorAll('[data-session-id]')].find(node=>node.getAttribute('data-session-id')===${JSON.stringify(stopSessionId)});if(row)row.click();return !!row})()`)
+    await wait(`[...document.querySelectorAll('.cr-self-bubble')].some(node=>node.textContent.includes(${JSON.stringify(stopMessage)}))`, 'session restored after switching back')
+    snapshots.switchedBack = await read(`(()=>({user:[...document.querySelectorAll('.cr-self-bubble')].some(node=>node.textContent.includes(${JSON.stringify(stopMessage)})),
+      streaming:!!document.querySelector('.wb-cr-streaming-footer'),stop:!!document.querySelector('button[aria-label="停止"]')}))()`)
+    check('switching tasks mid-turn keeps the message and the running turn', snapshots.switchedBack.user && snapshots.switchedBack.streaming && snapshots.switchedBack.stop, true)
+    await read(`document.querySelector('button[aria-label="停止"]').click()`)
+    await wait(`window.ycode.session.messages(${JSON.stringify(stopSessionId)}).then(list=>list.at(-1)?.status==='cancelled')`, 'turn cancelled')
+    await pause(250)
+    snapshots.stopped = await read(`(()=>({userBubbles:[...document.querySelectorAll('.cr-self-bubble')].map(node=>node.textContent.trim()),
+      cancelled:!!document.querySelector('.cr-cancelled-indicator'),streaming:!!document.querySelector('.wb-cr-streaming-footer'),
+      prepare:document.body.textContent.includes('正在启动对话运行环境…')}))()`)
+    check('cancelled turn keeps exactly one user message', snapshots.stopped.userBubbles.length, 1)
+    check('cancelled turn shows the cancelled indicator', snapshots.stopped.cancelled, true)
+    check('cancelled turn leaves no streaming placeholder', snapshots.stopped.streaming, false)
+    check('cancelled turn leaves no startup placeholder', snapshots.stopped.prepare, false)
+    check('no renderer error logs', rendererErrors, [])
+
+    const report = { result: checks.every(item => item.pass) ? 'PASS' : 'FAIL',
+      scope: 'Real isolated YCode App/preload/IPC/renderer with real OMP and a controlled local upstream; new-task send timing, startup placeholder, real-turn replacement and failure recovery measured in the live window.',
+      sourceEvidence: ['ev_717fa5e846e64d67ac19c8925d121bff632c0d3aefb3603b10858559cabb2dcb', 'docs/对话启动提示文案-2026-10-16.md', '.tmp/todo08-wb-new-task/notes.md'],
+      snapshots, checks, rendererErrors }
+    await fs.writeFile(path.join(directory, 'report.json'), JSON.stringify(report, null, 2))
+    console.log('NEW_TASK_SWITCH_' + report.result + ' ' + directory)
+    for (const failure of checks.filter(item => !item.pass)) console.log('NEW_TASK_SWITCH_FAILURE ' + JSON.stringify(failure))
+    server.close()
+    app.exit(report.result === 'PASS' ? 0 : 1)
+  })().catch(async error => {
+    await fs.writeFile(path.join(directory, 'failure.json'), JSON.stringify({ phase, error: String(error), stack: error.stack, checks, snapshots, rendererErrors }, null, 2))
+    console.error(error)
+    server?.close()
+    app.exit(1)
+  })
+}
diff --git a/src/renderer/src/components/ChatPane.tsx b/src/renderer/src/components/ChatPane.tsx
index 265a0e8..4ccbe91 100644
--- a/src/renderer/src/components/ChatPane.tsx
+++ b/src/renderer/src/components/ChatPane.tsx
@@ -221,10 +221,22 @@ export default function ChatPane({ rightVisible, onToggleRight, onOpenSettings,
   const submit = async ({ text, attachments, resources, quotes, mode }: ComposerSendPayload): Promise<void> => {
     if ((!text && !attachments.length && !quotes.length) || running || sending) return
     followBottom.current = true
-    await send(text, { attachments, resources, quotes, skillIds: entry.skills?.map(item => item.id), permissionMode: mode })
-    const destination = draftMoves.current.get(draftKey) ?? draftKey
-    draftMoves.current.delete(draftKey)
-    setDrafts((all) => ({ ...all, [draftKey]: { text: '', attachments: [] }, [destination]: { text: '', attachments: [] } }))
+    // 原版发送即清空输入框并立即切到对话页：先清空草稿，失败时再恢复（TODO 08）。
+    const submitKey = draftKey
+    const restore = { ...entry, text, attachments, resources, quotes }
+    setDrafts((all) => ({ ...all, [submitKey]: { text: '', attachments: [] } }))
+    try {
+      await send(text, { attachments, resources, quotes, skillIds: entry.skills?.map(item => item.id), permissionMode: mode })
+      // 会话创建后草稿所有权已迁移到会话 id；两处都清空，避免留下旧文本。
+      const destination = draftMoves.current.get(submitKey) ?? submitKey
+      draftMoves.current.delete(submitKey)
+      setDrafts((all) => ({ ...all, [submitKey]: { text: '', attachments: [] }, [destination]: { text: '', attachments: [] } }))
+    } catch (error) {
+      const destination = draftMoves.current.get(submitKey)
+      draftMoves.current.delete(submitKey)
+      setDrafts((all) => ({ ...all, [submitKey]: restore, ...(destination && destination !== submitKey ? { [destination]: restore } : {}) }))
+      throw error
+    }
   }
 
   /** 就地编辑：进入、取消、提交（提交走 send 的 action='edit' 分支，与原版 message.edit.submit 对齐）。 */
diff --git a/src/renderer/src/components/MessageBubble.tsx b/src/renderer/src/components/MessageBubble.tsx
index 1e4c5c7..78867be 100644
--- a/src/renderer/src/components/MessageBubble.tsx
+++ b/src/renderer/src/components/MessageBubble.tsx
@@ -23,6 +23,7 @@ import type { InteractionResponse, MessageQuote, PlanContent } from '@shared/con
 import MarkdownContent from './MarkdownContent'
 import StreamingFooter from '../workbuddy/conversation/StreamingFooter'
 import StreamingTurnDuration from '../workbuddy/conversation/StreamingTurnDuration'
+import { resolvePrepareText } from '../workbuddy/conversation/prepare-phases'
 import { getMessageParts } from '@shared/message-parts'
 import { projectWorkBuddyHistoryTool } from '@shared/workbuddy-history-projection'
 import { MessageQuoteTag } from '../workbuddy/conversation/MessageQuoteTag'
@@ -265,7 +266,7 @@ export default function MessageBubble({ message, onQuote, quotedSourceIds, darkM
           return option ? onRespond?.(id, { kind: 'approval', optionId: option.optionId }) : undefined
         }} /> : interaction.answer && !message.tools?.some((tool) => tool.id === interaction.toolCallId && tool.metadata?.questionAnswer) ? <QuestionAnswerTranscript key={interaction.id} questionAnswer={interaction.answer} /> : null)}
 
-      {streaming && <StreamingFooter />}
+      {streaming && <StreamingFooter prepareText={resolvePrepareText(message.prepareStage)} />}
 
       {message.status === 'error' && message.error ? (
         <div className="msg__status msg__status--error">{message.error}</div>
diff --git a/src/renderer/src/stores/chat.ts b/src/renderer/src/stores/chat.ts
index f8d23b6..da806d9 100644
--- a/src/renderer/src/stores/chat.ts
+++ b/src/renderer/src/stores/chat.ts
@@ -8,10 +8,30 @@ import type { ThinkingLevel } from '@shared/workspaces'
 import type { AgentMode } from '@shared/conversation'
 import { expertText, type ExpertActivation } from '@shared/capabilities'
 import { ChatStreamCommitter, type ChatStreamKey } from './chat-stream-committer'
+import { PENDING_START_STAGE } from '../workbuddy/conversation/prepare-phases'
 
 interface SummonExpertOptions { newTask?: boolean; initPrompt?: string }
 
 interface RunningState { runId: string; assistantId: string; sessionId?: string }
+
+/**
+ * 新任务发送后、主进程回合就绪前渲染的乐观占位（用户消息 + 助手占位）。
+ * id 以 local- 开头，只在渲染进程存在；真实消息到达或被替换/清理。
+ */
+function optimisticStartMessages(draftOwner: string, text: string, options: Omit<SendPayload, 'sessionId' | 'text'>): ChatMessage[] {
+  const startedAt = Date.now()
+  return [
+    { id: `local-user-${draftOwner}`, role: 'user', content: text, createdAt: startedAt, status: 'done',
+      attachments: options.attachments, resources: options.resources, quotes: options.quotes },
+    { id: `local-assistant-${draftOwner}`, role: 'assistant', content: '', tools: [], parts: [],
+      createdAt: startedAt, turnStartedAt: startedAt, status: 'streaming', prepareStage: PENDING_START_STAGE }
+  ]
+}
+
+function isOptimisticStartMessage(message: ChatMessage): boolean {
+  return message.id.startsWith('local-user-') || message.id.startsWith('local-assistant-')
+}
+
 interface ChatState {
   sessions: SessionMeta[]
   currentSessionId: string | null
@@ -27,7 +47,7 @@ interface ChatState {
   draftId: number
   init(): Promise<void>
   selectSession(id: string): Promise<void>
-  newSession(context?: SessionContext): Promise<SessionMeta>
+  newSession(context?: SessionContext, seedMessages?: ChatMessage[]): Promise<SessionMeta>
   startTask(context?: SessionContext): void
   selectModel(id: string): Promise<void>
   selectExpert(id: string | null): Promise<void>
@@ -225,14 +245,14 @@ export const useChatStore = create<ChatState>((set, get) => {
       window.dispatchEvent(new CustomEvent('ycode:expert-input', { detail: { owner: targetOwner, clear: true } }))
     }
   },
-  async newSession(context) {
+  async newSession(context, seedMessages: ChatMessage[] = []) {
     const previousSessionId = get().currentSessionId
     if (previousSessionId) streamCommitter.flushSession(previousSessionId)
     const version = ++selectionVersion
     const created = await window.ycode.session.create(undefined, context)
     set((state) => ({ sessions: [created, ...state.sessions],
-      sessionMessages: { ...state.sessionMessages, [created.id]: [] },
-      ...(version === selectionVersion ? { currentSessionId: created.id, messages: [], running: null,
+      sessionMessages: { ...state.sessionMessages, [created.id]: seedMessages },
+      ...(version === selectionVersion ? { currentSessionId: created.id, messages: seedMessages, running: null,
         sending: false, loading: false, error: null } : {}) }))
     return created
   },
@@ -286,13 +306,20 @@ export const useChatStore = create<ChatState>((set, get) => {
     let sessionId = get().currentSessionId
     if (!sessionId) {
       if (get().sending) return
+      // 原版在新任务发送后立即切到对话页：先渲染乐观的「用户消息 + 助手占位」，
+      // 等主进程建好会话与回合（可能包含运行环境启动）后再用真实消息替换（TODO 08）。
       const draftOwner = `new-${get().draftId}`
-      set({ sending: true })
+      const optimistic = optimisticStartMessages(draftOwner, trimmed, options)
+      set({ sending: true, messages: optimistic })
       try {
-        sessionId = (await get().newSession({ ...get().draftContext })).id
+        sessionId = (await get().newSession({ ...get().draftContext }, optimistic)).id
         if (typeof window.dispatchEvent === 'function') window.dispatchEvent(new CustomEvent('ycode:composer-owner-migrated', { detail: { from: draftOwner, to: sessionId } }))
       }
-      catch (error) { set({ sending: false }); throw error }
+      catch (error) {
+        set((state) => ({ sending: false, messages: state.currentSessionId === null ? [] : state.messages,
+          error: error instanceof Error ? error.message : String(error) }))
+        throw error
+      }
     }
     if (!sessionId || get().sendingSessions.includes(sessionId) || currentRun(get().runs, sessionId)) return
     const owner = sessionId
@@ -306,7 +333,8 @@ export const useChatStore = create<ChatState>((set, get) => {
         assistantDisplay: result.assistantDisplay, createdAt: Date.now(),
         turnStartedAt: result.userMessage.createdAt, status: 'streaming' }
       set((state) => {
-        const history = state.currentSessionId === owner ? state.messages : state.sessionMessages[owner] ?? []
+        const history = (state.currentSessionId === owner ? state.messages : state.sessionMessages[owner] ?? [])
+          .filter((item) => !isOptimisticStartMessage(item))
         const messages = result.messages ?? [...history, result.userMessage, placeholder]
         const running = { runId: result.runId, assistantId: result.assistantMessageId, sessionId: owner }
         return { sessionMessages: { ...state.sessionMessages, [owner]: messages },
@@ -320,8 +348,14 @@ export const useChatStore = create<ChatState>((set, get) => {
       void window.ycode.session.list().then((sessions) => set({ sessions })).catch(() => undefined)
     } catch (error) {
       pendingEvents.delete(owner)
-      set((state) => ({ sendingSessions: state.sendingSessions.filter((id) => id !== owner),
-        ...(state.currentSessionId === owner ? { sending: false, error: error instanceof Error ? error.message : String(error) } : {}) }))
+      // 首条消息发送失败：移除乐观占位（用户草稿由输入框恢复），不留下未持久化的消息。
+      set((state) => {
+        const base = state.currentSessionId === owner ? state.messages : state.sessionMessages[owner] ?? []
+        const cleaned = base.filter((item) => !isOptimisticStartMessage(item))
+        return { sessionMessages: { ...state.sessionMessages, [owner]: cleaned },
+          sendingSessions: state.sendingSessions.filter((id) => id !== owner),
+          ...(state.currentSessionId === owner ? { messages: cleaned, sending: false, error: error instanceof Error ? error.message : String(error) } : {}) }
+      })
       throw error
     }
   },
diff --git a/src/renderer/src/workbuddy/conversation/StreamingFooter.tsx b/src/renderer/src/workbuddy/conversation/StreamingFooter.tsx
index 0779118..05ef1c2 100644
--- a/src/renderer/src/workbuddy/conversation/StreamingFooter.tsx
+++ b/src/renderer/src/workbuddy/conversation/StreamingFooter.tsx
@@ -97,9 +97,11 @@ function activeBrandName(): string {
 
 export interface StreamingFooterProps {
   locale?: string
+  /** 新任务启动阶段文案（原版 chat.prepare.<stage>）；提供时替换「思考中」。 */
+  prepareText?: string | null
 }
 
-export function StreamingFooter({ locale }: StreamingFooterProps): React.JSX.Element {
+export function StreamingFooter({ locale, prepareText }: StreamingFooterProps): React.JSX.Element {
   const resolvedLocale = locale ?? activeLocale()
   const brandName = activeBrandName()
   const tips = useMemo(() => getSourceLoadingTips(resolvedLocale, brandName), [brandName, resolvedLocale])
@@ -112,7 +114,7 @@ export function StreamingFooter({ locale }: StreamingFooterProps): React.JSX.Ele
     isPaused: () => isPaused.current
   }), [tips])
 
-  const thinkingLabel = conversationLabel('message.loading.thinking', {}, resolveLoadingTipLocale(resolvedLocale) === 'en' ? 'en' : 'zh-cn')
+  const thinkingLabel = prepareText ?? conversationLabel('message.loading.thinking', {}, resolveLoadingTipLocale(resolvedLocale) === 'en' ? 'en' : 'zh-cn')
 
   return <div className="wb-cr-streaming-footer">
     <div className="_loadingWithCredit_ttf8p_463" style={{ '--cb-assistant-inline-padding': '0px' } as CSSProperties}>
diff --git a/src/renderer/src/workbuddy/conversation/prepare-phases.ts b/src/renderer/src/workbuddy/conversation/prepare-phases.ts
new file mode 100644
index 0000000..f5808ad
--- /dev/null
+++ b/src/renderer/src/workbuddy/conversation/prepare-phases.ts
@@ -0,0 +1,29 @@
+// Recovered from REA ev_717fa5e846e64d67ac19c8925d121bff632c0d3aefb3603b10858559cabb2dcb
+// (WorkBuddy 5.8.2 renderer/assets/contexts-BMeWSUHk.js, SHA-256
+// 5f35b7489b107e21ef452c8ee88a95265756f6fc444841eef869228bbc44768b);
+// 文案表与显示逻辑见 docs/对话启动提示文案-2026-10-16.md。
+// 原版按会话 prepareStatus.stage 选择 chat.prepare.<stage>；YCode 的 chat:send 在
+// 主进程启动运行环境期间是单个阻塞阶段，因此发送后的占位只使用 acquiring_runtime，
+// 不按字符串表臆造原版阶段顺序与持续时长。
+export const CONVERSATION_PREPARE_TEXT = {
+  expert: '正在准备专家能力…',
+  reading_conversation_settings: '正在读取对话设置…',
+  resolving_system_prompt: '正在生成系统提示词…',
+  configuring_model_and_tools: '正在配置模型与工具…',
+  resolving_skill_requirements: '正在整理技能配置…',
+  resolving_plugin_requirements: '正在整理插件配置…',
+  preparing_environment: '正在准备运行环境…',
+  mcp: '正在整理连接器配置…',
+  checking_launch_config: '正在检查启动配置…',
+  acquiring_runtime: '正在启动对话运行环境…'
+} as const
+
+export type ConversationPrepareStage = keyof typeof CONVERSATION_PREPARE_TEXT
+
+/** 新任务发送后、主进程回合就绪前的占位阶段（对应运行环境启动）。 */
+export const PENDING_START_STAGE: ConversationPrepareStage = 'acquiring_runtime'
+
+export function resolvePrepareText(stage: string | null | undefined): string | null {
+  if (!stage) return null
+  return stage in CONVERSATION_PREPARE_TEXT ? CONVERSATION_PREPARE_TEXT[stage as ConversationPrepareStage] : null
+}
diff --git a/src/shared/types.ts b/src/shared/types.ts
index 96e0f75..1c6f01d 100644
--- a/src/shared/types.ts
+++ b/src/shared/types.ts
@@ -43,6 +43,8 @@ export interface ChatMessage {
   /** 本回合的终态 */
   status?: 'streaming' | 'done' | 'error' | 'cancelled'
   error?: string
+  /** 渲染进程专用的启动占位阶段（新任务发送后、主进程回合就绪前）；不参与持久化。 */
+  prepareStage?: string
 }
 
 export interface ToolCallRecord {