fix(client): restore assistant timing from recorded streams

.agents/notes/implemented/architecture/2026-09-06-embedded-stream-record-readers.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write .agents/notes/implemented/architecture/2026-09-06-embedded-stream-record-readers.md
-2026-09-06-embedded-stream-record-readers.md: 972fee634833cef5fd7b0a54f69780b9370f0cc3
-2026-09-06-embedded-stream-record-readers.zh.md: faba6e179887a9943926f2c73aa8e42a10cee300
+2026-09-06-embedded-stream-record-readers.md: 76e109de577d070093bb7123aa50d9a4ae7fcbe5
+2026-09-06-embedded-stream-record-readers.zh.md: 33f4b31117197c47e7f2ff1637bc13fa2cbf1a8c

.agents/notes/implemented/architecture/2026-09-06-embedded-stream-record-readers.md

@@ -20,7 +20,7 @@ After v2 embedded streams settlement widened with the message content and Chat a
 - Run readers: `runFirstTokenTime` and `runFirstVisibleTime` reconstruct the first qualifying member's time from `time0` and the `dt` gaps and stop scanning there; a name-bearing Tool-call run yields `time0` without reading a fragment.
 - Stream readers: `assistantStreamFirstTokenTime`, `assistantStreamHasVisibleContent`, `assistantStreamHasVisibleText`, `lastAssistantStreamChunk(stream, type)` (backward scan), `assistantStreamChunks(stream, type)`, `joinAssistantStreamText`, and `assembleAssistantStream`, which feeds a `BlockAssembler` one joined delta per run (assembly only concatenates, so blocks, usage, finish, and replay state equal the per-member result). `RawStreamChunkType` excludes the delta types, so a raw-chunk lookup can never silently skip packed members.
 
-Session Stats reads `assistantStreamFirstTokenTime`; the token meter reads `lastAssistantStreamChunk(stream, 'usage')` and assembles provider output through `assembleAssistantStream`; the subagent output fold appends `joinAssistantStreamText`; the Session Controller scans `assistantStreamChunks(stream, 'block-end')` for images.
+Session Stats, Chat, and Trajectory read `assistantStreamFirstTokenTime` from both `assistant/attempt` and `assistant/message`, retaining the Step's first token across retries. Chat and Trajectory settle content from the assembled message while reading timing independently, so reopening history retains TTFT and decoding metrics without expanding streams. The token meter reads `lastAssistantStreamChunk(stream, 'usage')` and assembles provider output through `assembleAssistantStream`; the subagent output fold appends `joinAssistantStreamText`; the Session Controller scans `assistantStreamChunks(stream, 'block-end')` for images.
 
 `expandAssistantStream` keeps its strict validation and its remaining callers, which need every member or validate the stream at a durable boundary: Session restore validation, the v1-to-v2 migration validator and publication Worker replay, the reconnect baseline, and test support.
 

.agents/notes/implemented/architecture/2026-09-06-embedded-stream-record-readers.zh.md

@@ -20,7 +20,7 @@ Session 格式 v2 将每次模型尝试的紧凑流（`AssistantStreamRecord[]`
 - Run 读取器：`runFirstTokenTime` 与 `runFirstVisibleTime` 从 `time0` 与 `dt` 间隔重建首个合格成员的时间并停止扫描；带名称的 Tool-call run 直接产出 `time0`，不读片段。
 - 流读取器：`assistantStreamFirstTokenTime`、`assistantStreamHasVisibleContent`、`assistantStreamHasVisibleText`、`lastAssistantStreamChunk(stream, type)`（逆向扫描）、`assistantStreamChunks(stream, type)`、`joinAssistantStreamText` 与 `assembleAssistantStream`（每个 run 向 `BlockAssembler` 喂入一个拼接后的 delta；组装只做拼接，因此 blocks、usage、finish 与 replay state 与逐成员结果一致）。`RawStreamChunkType` 排除 delta 类型，因此原始 chunk 查找不可能静默跳过打包成员。
 
-Session Stats 读取 `assistantStreamFirstTokenTime`；token 计量读取 `lastAssistantStreamChunk(stream, 'usage')` 并通过 `assembleAssistantStream` 组装提供商输出；子代理输出折叠追加 `joinAssistantStreamText`；Session Controller 用 `assistantStreamChunks(stream, 'block-end')` 扫描镜像。
+Session Stats、Chat 与 Trajectory 从 `assistant/attempt` 和 `assistant/message` 读取 `assistantStreamFirstTokenTime`，跨重试保留步骤的首个 token。Chat 与 Trajectory 从组装后的消息结算内容，并独立读取计时，因此重新打开历史时无需展开流便能保留 TTFT 与解码指标。token 计量读取 `lastAssistantStreamChunk(stream, 'usage')` 并通过 `assembleAssistantStream` 组装提供商输出；子代理输出折叠追加 `joinAssistantStreamText`；Session Controller 用 `assistantStreamChunks(stream, 'block-end')` 扫描镜像。
 
 `expandAssistantStream` 保留其严格校验与其余调用方（需要每个成员或在持久边界校验流）：Session 恢复校验、v1-to-v2 迁移校验器与发布 Worker 重放、重连基线、测试支撑。
 

apps/web/tests/navigation-panes.e2e.ts

@@ -24,6 +24,7 @@ import { expandOwningTurnProcess, newEnglishPage, saveFailureShot } from './supp
 const SNAPSHOT_DIR = fileURLToPath(new URL('../../../snapshots/web/navigation-panes', import.meta.url))
 const SEED = join(SNAPSHOT_DIR, 'session.v3.jsonl')
 const TRAJECTORY_EXPECTED = join(SNAPSHOT_DIR, 'trajectory.expected.md')
+const TIMING_EXPECTED = join(SNAPSHOT_DIR, 'timing.expected.md')
 const SEARCH_EXPECTED = join(SNAPSHOT_DIR, 'search-results.expected.md')
 const TERMINAL_EXPECTED = join(SNAPSHOT_DIR, 'terminal-card.expected.md')
 const MODE = webSnapshotMode()
@@ -97,7 +98,8 @@ describe('web e2e: navigation & panes over a rich seeded session', () => {
       const raw = await readFile(SEED, 'utf8')
       expect(fixtureUserPrompts(raw), 'seed fixture must carry exactly the two drive prompts')
         .toEqual([PROMPT_TURN1, PROMPT_TURN2])
-      await seedSession(scaffold, raw, SEED_ID)
+      // The inspector's calendar date must not depend on the day the test runs.
+      await seedSession(scaffold, raw, SEED_ID, undefined, { createdAt: Date.UTC(2026, 0, 1) })
     }
     browser = await chromium.launch()
   }, 120_000)
@@ -264,13 +266,30 @@ describe('web e2e: navigation & panes over a rich seeded session', () => {
     await page.evaluate(() => { document.body.removeAttribute('data-ds-dark-theme') })
     await page.getByRole('tab', { name: 'Result' }).click()
     await expect.poll(() => page.getByText('NAVIGATION_OK', { exact: false }).count(), { timeout: 10_000 }).toBeGreaterThanOrEqual(1)
-    expect(await page.locator('[data-timeline-span="message"][data-assistant-timing="true"]').count()).toBe(0)
+    expect(await page.locator('[data-timeline-span="message"][data-assistant-timing="true"]').count()).toBeGreaterThan(0)
     const snapshot = (await captureStableAria(page, '[class*="viewArea"]', scaffold.workspaceCwd))
       .split(SEED_ID).join('{{seededId}}')
     await compareOrRefreshGolden(TRAJECTORY_EXPECTED, snapshot, MODE)
     await details.getByRole('button', { name: 'Close details' }).click()
   }, 60_000)
 
+  it.skipIf(MODE === 'record')('restores Assistant timing from recorded history', async () => {
+    onTestFailed(() => saveFailureShot(page, 'web-e2e-navigation-timing'))
+    await ensureSeedOpen(page)
+    await page.getByRole('tab', { name: 'Trajectory' }).click()
+    await page.getByRole('button', { name: 'Request #1', exact: true }).click()
+    const details = page.getByRole('complementary', { name: 'Event details' })
+    await details.getByRole('tab', { name: 'Timing', exact: true }).click()
+    const panel = details.getByRole('tabpanel', { name: 'Timing' })
+    for (const metric of ['TTFT', 'Generation', 'Throughput']) {
+      const value = panel.getByText(metric, { exact: true }).locator('..').locator('dd')
+      await expect.poll(() => value.textContent()).toMatch(/^\d/)
+    }
+    expect(await panel.getByText('First token unavailable', { exact: true }).count()).toBe(0)
+    const snapshot = await captureStableAria(page, '#trajectory-detail-panel', scaffold.workspaceCwd)
+    await compareOrRefreshGolden(TIMING_EXPECTED, snapshot, MODE)
+  }, 60_000)
+
   it.skipIf(MODE === 'record')('downloads through the Session Header and /export with one dialog', async () => {
     onTestFailed(() => saveFailureShot(page, 'web-e2e-navigation-export'))
     await ensureSeedOpen(page)
@@ -505,7 +524,7 @@ describe('web e2e: navigation & panes over a rich seeded session', () => {
   it.skipIf(MODE === 'record')('keeps the recorded fixture inventory exact', async () => {
     await assertFixtureInventory(SNAPSHOT_DIR, [
       'session.v3.jsonl', 'search-results.expected.md', 'trajectory.expected.md',
-      'terminal-card.expected.md',
+      'terminal-card.expected.md', 'timing.expected.md',
     ])
   })
 })

apps/web/tests/turn-tail-actions.e2e.ts

@@ -201,8 +201,8 @@ describe('web e2e: assistant IconActions wait for the turn to end', () => {
     await timeTrigger.click()
     const timeDialog = page.getByRole('dialog', { name: 'Turn time and speed' })
     expect(await timeDialog.count()).toBe(1)
-    expect(await timeDialog.getByText(/tok\/s/).count()).toBe(0)
-    expect(await timeDialog.getByText('Time to first token (TTFT)', { exact: true }).count()).toBe(0)
+    expect(await timeDialog.getByText(/tok\/s/).count()).toBeGreaterThan(0)
+    expect(await timeDialog.getByText('Time to first token (TTFT)', { exact: true }).count()).toBe(1)
     await page.keyboard.press('Escape')
     await trigger.click()
 

packages/client/ui-chat/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/client/ui-chat/README.md
-README.md: 860dcb9eeb9c92a14d9128d9d8c95c29796726f8
-README.zh.md: 4dd06a16b19b14cacc0ded603cc1cf8869dd1a43
+README.md: 3e99cd599a834a9629193015e9d76468bf6480f4
+README.zh.md: d431cf567dda8d78ef2c696959ae2574feaa49d3

packages/client/ui-chat/README.md

@@ -34,6 +34,8 @@ Each nonempty appended `system/message` owns a collapsed prompt row, including a
 
 A completed Turn shows an expandable usage row only when the loaded window includes `turn/start` and every started model attempt reports safe, exact usage. The row omits unavailable optional buckets. Incomplete or contradictory accounting hides the complete disclosure instead of presenting a partial total.
 
+Reply timing survives reopening history: recorded token timestamps supply first-token latency and generation duration, including the Step's first token from an earlier retry attempt. Missing Step starts or token timestamps leave the affected metrics unavailable.
+
 -----
 
 <a id="turn-process-folding"></a>

packages/client/ui-chat/README.zh.md

@@ -36,6 +36,8 @@ kind: "package-reference"
 
 只有当已加载窗口包含 `turn/start`，且每次已启动的模型尝试都报告安全、精确的用量时，已完成 Turn 才显示可展开的用量行。该行会省略不可用的可选用量桶。记账不完整或相互矛盾时，整个详情都不显示，避免把部分总量冒充完整结果。
 
+重新打开历史后仍保留回复计时：记录中的 token 时间戳提供首 token 延迟和生成耗时，包括步骤中更早重试尝试的首个 token。缺少步骤起点或 token 时间戳时，受影响的指标保持不可用。
+
 -----
 
 <a id="turn-process-folding"></a>

packages/client/ui-chat/src/client/conversation-nodes/assistant.ts

@@ -4,6 +4,7 @@ import type {
   ConversationNodeContext, ConversationNodeDefinition,
 } from '@deepseek-ai/dsh-client-ui-conversation/client'
 import type { StreamChunk } from '@deepseek-ai/dsh-llm'
+import { assistantStreamFirstTokenTime } from '@deepseek-ai/dsh-llm/assistant-stream'
 import type {} from '@deepseek-ai/dsh-llm-retry/types'
 import type { SessionEvent } from '@deepseek-ai/dsh-session/types'
 import type { AssistantChatData } from '../contract/chat-nodes.ts'
@@ -161,6 +162,17 @@ function updateChunk(
   }
 }
 
+/** The Step retains its first token across live chunks and settled retry attempts. */
+function settleTiming(
+  state: AssistantState,
+  event: SessionEvent<'assistant/message' | 'assistant/attempt'>,
+): AssistantState {
+  return {
+    ...state,
+    firstTokenTime: state.firstTokenTime ?? assistantStreamFirstTokenTime(event.data.stream),
+  }
+}
+
 function settleMessage(
   state: AssistantState,
   match: ConversationMatch,
@@ -168,7 +180,7 @@ function settleMessage(
 ): AssistantState {
   const blocks = toAssistantBlocks(event.data.message.content)
   return {
-    ...state,
+    ...settleTiming(state, event),
     blocks,
     visibleBlocks: countVisibleBlocks(blocks),
     hidden: false,
@@ -236,6 +248,11 @@ function fallbackState(context: ConversationNodeContext<AssistantState>): Assist
       state = updateChunk(state, match.event.data.chunk, match.event.seq, match.event.time)
       continue
     }
+    if (match.event.type === 'assistant/attempt') {
+      state ??= initialState(match.event.data.turn, match.event.data.step)
+      state = settleTiming(state, match.event)
+      continue
+    }
     if (match.event.type === 'assistant/message') {
       state ??= initialState(match.event.data.turn, match.event.data.step)
       state = settleMessage(state, match, match.event)
@@ -296,6 +313,7 @@ export const assistantDefinition: ConversationNodeDefinition<AssistantState> = {
   match: (event) => {
     if (event.type === 'step/start') return { id: `${event.data.turn}:${event.data.step}`, role: 'start' }
     if (event.type === 'assistant/live-chunk'
+      || event.type === 'assistant/attempt'
       || (event.type === 'assistant/message' && event.surfaceOp === 'append')) {
       return { id: `${event.data.turn}:${event.data.step}`, role: 'update' }
     }
@@ -313,13 +331,14 @@ export const assistantDefinition: ConversationNodeDefinition<AssistantState> = {
       return updateChunk(context.state, match.event.data.chunk, match.event.seq, match.event.time)
     }
     if (match.event.type === 'assistant/message') return settleMessage(context.state, match, match.event)
+    if (match.event.type === 'assistant/attempt') return settleTiming(context.state, match.event)
     if (match.event.type === 'llm/retry') {
       return resetForRetry(context.state)
     }
     return context.state
   },
   publication: (match) => {
-    if (match.event.type === 'step/start') return 'none'
+    if (match.event.type === 'step/start' || match.event.type === 'assistant/attempt') return 'none'
     if (match.event.type !== 'assistant/live-chunk') return 'immediate'
     const type = match.event.data.chunk.type
     return type === 'usage' || type === 'finish' ? 'none' : 'animation-frame'

packages/client/ui-chat/tests/conversation-node-definitions.client.spec.ts

@@ -1056,9 +1056,16 @@ describe('built-in conversation node Definitions', () => {
     const finalNode = (node(finalizedPacked, 'assistant-step')?.data as AssistantChatData).finalNode
     expect(finalNode).toMatchObject({
       blocks: [{ kind: 'text', text: 'done' }],
-      timing: { firstTokenTime: null },
+      timing: { firstTokenTime: 1_999 },
     })
 
+    const windowed = assembler(finalizedInputs.slice(2), true)
+    const timing = () => (node(snapshot(windowed), 'assistant-step')?.data as AssistantChatData).finalNode?.timing
+    expect(timing()).toMatchObject({ stepStartTime: null, firstTokenTime: 1_999 })
+    windowed.prepend(finalizedInputs.slice(0, 2), false)
+    windowed.flush()
+    expect(timing()).toEqual(finalNode?.timing)
+
     const namedToolHistory = [
       at(40, 'turn/start', { turn: 3 }),
       at(41, 'step/start', { turn: 3, step: 1 }),
@@ -1083,7 +1090,7 @@ describe('built-in conversation node Definitions', () => {
     const namedTool = (node(namedToolPacked, 'assistant-step')?.data as AssistantChatData).finalNode
     expect(namedTool).toMatchObject({
       blocks: [{ kind: 'tool-call', callId: 'call-2', name: 'read', argsRaw: '' }],
-      timing: { firstTokenTime: null },
+      timing: { firstTokenTime: 4_000 },
     })
   })
 

packages/client/ui-trajectory/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/client/ui-trajectory/README.md
-README.md: 2b8ecff50b498be529ccf7e35e528f7554084940
-README.zh.md: 8463bd0a68c32753138425d968db229726b5bd1a
+README.md: 099ce8c9330040e106ab4ab1bfbf155d32a38e79
+README.zh.md: 7b00cd8ccf8dfdc36f6df55e3b0e7c1ae8fe5847

packages/client/ui-trajectory/README.md

@@ -33,6 +33,8 @@ Selection, timeline navigation, folding, and search cover the React-visible wind
 
 ### The timing overview
 
+Historical replies retain TTFT, generation duration, and throughput when their recorded streams contain token timestamps. TTFT measures from the Step start to its first token, including output from an earlier retry attempt; an unloaded Step start or a stream without tokens leaves the corresponding metric unavailable.
+
 A fixed Overview above the ledger projects real record start/duration timing from left to right; Assistant spans divide recorded TTFT from decoding, and a 500 ms hover reveals exact clock and duration details. Dragging an interval focuses the ledger on every record active at any point in that inclusive range; wheel gestures zoom the time domain; a right-button click clears the selected interval, and a right-button drag pans an already zoomed viewport. The initial view and streaming updates stay at the tail; scrolling upward suspends following so new records do not interrupt inspection of earlier rows.
 
 -----

packages/client/ui-trajectory/README.zh.md

@@ -33,6 +33,8 @@ Trajectory 标签页让你以按轮次组织的事件记录表和交互式时间
 
 ### 时间概览
 
+当记录的流包含 token 时间戳时，历史回复会保留 TTFT、生成耗时与吞吐量。TTFT 从步骤开始计量到首个 token，包括更早重试尝试中的输出；步骤起点尚未加载或流中没有 token 时，对应指标保持不可用。
+
 固定在记录表上方的 Overview 区域从左到右投影记录的真实开始时间与耗时；助手时间条区分记录到的 TTFT 与解码时间，悬停 500 ms 后可查看精确时刻与耗时详情。拖选区间会把记录表聚焦到该闭区间内任何时刻处于活动的记录；滚轮手势用于缩放时间域；右键单击会清除所选区间，在已放大的视口上按住右键拖动则会平移。初始视图与流式更新都停留在尾部；向上滚动会暂停跟随，因此新记录不会打断对旧记录的检查。
 
 -----

packages/client/ui-trajectory/src/client/trajectory-assistant-definition.ts

@@ -5,6 +5,7 @@ import type {
   PartialAssistant, RequestView,
 } from '@deepseek-ai/dsh-client-ui-conversation/client'
 import type { StreamChunk } from '@deepseek-ai/dsh-llm'
+import { assistantStreamFirstTokenTime } from '@deepseek-ai/dsh-llm/assistant-stream'
 import type { SessionEvent } from '@deepseek-ai/dsh-session/types'
 import { trajectoryNode } from './trajectory-definition-common.ts'
 import {
@@ -191,6 +192,17 @@ function updateChunk(
   }
 }
 
+/** The Step retains its first token across live chunks and settled retry attempts. */
+function settleTiming(
+  state: AssistantState,
+  event: SessionEvent<'assistant/message' | 'assistant/attempt'>,
+): AssistantState {
+  return {
+    ...state,
+    firstTokenTime: state.firstTokenTime ?? assistantStreamFirstTokenTime(event.data.stream),
+  }
+}
+
 function settleMessage(
   state: AssistantState,
   match: ConversationMatch,
@@ -198,7 +210,7 @@ function settleMessage(
 ): AssistantState {
   const blocks = toAssistantBlocks(event.data.message.content)
   return {
-    ...state,
+    ...settleTiming(state, event),
     sawChunk: false,
     blocks,
     visibleBlocks: countVisibleBlocks(blocks),
@@ -226,6 +238,9 @@ function fallbackState(context: ConversationNodeContext<AssistantState>): Assist
     if (event.type === 'assistant/live-chunk') {
       state ??= initialState(event.data.turn, event.data.step, event.seq, event.time, false)
       state = updateChunk(state, event.data.chunk, event.seq, event.time)
+    } else if (event.type === 'assistant/attempt') {
+      state ??= initialState(event.data.turn, event.data.step, event.seq, event.time, false)
+      state = settleTiming(state, event)
     } else if (event.type === 'assistant/message') {
       state ??= initialState(event.data.turn, event.data.step, event.seq, event.time, false)
       state = settleMessage(state, match, event)
@@ -325,6 +340,7 @@ const trajectoryAssistantDefinition: ConversationNodeDefinition<AssistantState>
     }
     if (event.type === 'assistant/live-chunk'
       || event.type === 'assistant/message'
+      || event.type === 'assistant/attempt'
       || event.type === 'llm/retry'
       || event.type === 'step/end') {
       return { id: `${event.data.turn}:${event.data.step}`, role: 'update' }
@@ -348,6 +364,7 @@ const trajectoryAssistantDefinition: ConversationNodeDefinition<AssistantState>
       return updateChunk(context.state, match.event.data.chunk, match.event.seq, match.event.time)
     }
     if (match.event.type === 'assistant/message') return settleMessage(context.state, match, match.event)
+    if (match.event.type === 'assistant/attempt') return settleTiming(context.state, match.event)
     if (match.event.type === 'step/end') return { ...context.state, stepEnd: match }
     if (match.event.type !== 'llm/retry') return context.state
     const data = match.event.data
@@ -372,7 +389,7 @@ const trajectoryAssistantDefinition: ConversationNodeDefinition<AssistantState>
     }
   },
   publication: (match) => {
-    if (match.event.type === 'step/start') return 'none'
+    if (match.event.type === 'step/start' || match.event.type === 'assistant/attempt') return 'none'
     if (match.event.type !== 'assistant/live-chunk') return 'immediate'
     const type = match.event.data.chunk.type
     return type === 'usage' || type === 'finish' ? 'none' : 'animation-frame'

packages/client/ui-trajectory/tests/conversation-definitions.client.spec.ts

@@ -335,13 +335,20 @@ describe('Trajectory conversation Definitions', () => {
     const finalizedPacked = snapshot(assembler(finalizedInputs))
     expect(finalizedPacked.eventNodes.find(node => node.kind === 'assistant')).toMatchObject({
       blocks: [{ kind: 'text', text: 'done' }],
-      timing: { firstTokenTime: null },
+      timing: { firstTokenTime: 3_000 },
     })
     expect(finalizedPacked.requests).toMatchObject([{
       purpose: 'assistant',
       retry: 1,
     }])
 
+    const windowed = assembler(finalizedInputs.slice(2), true)
+    const assistant = () => snapshot(windowed).eventNodes.find(node => node.kind === 'assistant')
+    expect(assistant()).toMatchObject({ timing: { stepStartTime: null, firstTokenTime: 3_000 } })
+    windowed.prepend(finalizedInputs.slice(0, 2), false)
+    windowed.flush()
+    expect(assistant()).toEqual(finalizedPacked.eventNodes.find(node => node.kind === 'assistant'))
+
     const namedToolHistory = [
       at(40, 'turn/start', { turn: 3 }),
       at(41, 'step/start', { turn: 3, step: 1 }),
@@ -365,7 +372,7 @@ describe('Trajectory conversation Definitions', () => {
     const namedToolPacked = snapshot(assembler(namedToolInputs))
     expect(namedToolPacked.eventNodes.find(node => node.kind === 'assistant')).toMatchObject({
       blocks: [{ kind: 'tool-call', callId: 'call-2', name: 'read', argsRaw: '' }],
-      timing: { firstTokenTime: null },
+      timing: { firstTokenTime: 4_000 },
     })
   })
 

snapshots/web/navigation-panes/timing.expected.md

@@ -0,0 +1,12 @@
+- tabpanel "Timing":
+  - term: Started
+  - definition:
+    - button "2026-01-01 {{clock}}"
+  - term: Total duration
+  - definition: {{duration}}
+  - term: TTFT
+  - definition: {{duration}}
+  - term: Generation
+  - definition: {{duration}}
+  - term: Throughput
+  - definition: {{throughput}} tok/s