Merge remote-tracking branch 'origin/master' into codex/status-bar-token-metrics

# Conflicts: # apps/web/tests/snapshots/code-mode-round/ui.expected.md # apps/web/tests/snapshots/cordis-tool-round/ui.expected.md # apps/web/tests/snapshots/fresh-round-trip/ui.expected.md # apps/web/tests/snapshots/lifecycle-chrome/reloaded.expected.md # apps/web/tests/snapshots/live-interactions/cancel.expected.md # apps/web/tests/snapshots/live-interactions/retry.expected.md # apps/web/tests/snapshots/seeded-history/ui.expected.md # apps/web/tests/snapshots/steering/mid-steer.expected.md # apps/web/tests/snapshots/steering/settled.expected.md # packages/client/ui-conversation/README.i18n.yaml
2026-07-29 15:36:38 +08:00
parent bf618dabf9 59ecfac776
commit d20e531153
63 changed files with 1111 additions and 246 deletions
--- a/packages/client/ui-conversation/README.i18n.yaml
+++ b/packages/client/ui-conversation/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-conversation/README.md
-README.md: c60a38ec26d4bca15ce23e51dbaedf3ef36022e4
-README.zh.md: 65c5554a78960fc4f86a6a370772c95429c648c4
+README.md: 4db28ced96abee8d2110abbd09a1c8761aac5d1d
+README.zh.md: 99822a88835103c471ca0364cd57cd13ea8a6434
--- a/packages/client/ui-conversation/README.md
+++ b/packages/client/ui-conversation/README.md
@@ -36,7 +36,7 @@ None; this package neither assembles nor sends a provider request.

 - **The stats line has no duration segment** — assistant `usage` carries token accounting only; elapsed-time needs a host data source.
 - **Details panel is the minimal form** — selected call args/result raw display; the Input/Output/Metadata switch, Prev/Next stepping, and See-in-trajectory deep link are deferred.
- **Assistant footer extensions (IconActions row, per-message paging) are reserved slots** — drawn in the design, not implemented.
+- **Assistant per-message paging is a reserved slot** — drawn in the design, not implemented. The finalized IconActions row (copy / branch / clock) ships; branch remains a chrome stub.
 - **The sparkle icon for the others tool row is a hand-drawn approximation** — the design glyph's vector geometry is not exportable locally; promotion into ui-primitives waits on an exact export.
 - **The approval panel's "Always allow this type" is deferred** — durable grants need a grant-storage design; only allow-once/reject answer today.
 - **TodoPanel truncates long item text to one ellipsized line** — the figma strip has no wrap or expand affordance; full text is not readable inline.
--- a/packages/client/ui-conversation/README.zh.md
+++ b/packages/client/ui-conversation/README.zh.md
@@ -36,7 +36,7 @@ todo 两个面就是在该形状上的两个注册项，都是普通注册方插

 - **统计行没有耗时区段**：assistant `usage` 只携带 token 计数；耗时需要主机数据源。
 - **详情面板是最小形态**：以原始形式显示已选择调用的参数／结果；Input/Output/Metadata 切换、Prev/Next 步进与 See-in-trajectory 深链接暂缓实现。
- **assistant footer 扩展（IconActions 行、逐消息分页）是预留 slot**：设计中已有图稿，尚未实现。
+- **assistant 逐消息分页是预留 slot**：设计中已有图稿，尚未实现。已定稿的 IconActions 行（复制／分支／时钟）已落地；分支仍是 chrome stub。
 - **others 工具行的闪光图标是手绘近似版本**：无法在本地导出设计字形的矢量几何；等到存在精确导出后再将其提升到 ui-primitives。
 - **审批面板的「始终允许此类」暂缓**：持久授权需要授权存储设计；今天只能回答允许一次／拒绝。
 - **TodoPanel 将过长条目截成单行省略号**：figma 条没有换行或展开入口，完整文本无法在行内读完。
--- a/packages/client/ui-conversation/src/client/chat/AssistantMarkdown.module.css
+++ b/packages/client/ui-conversation/src/client/chat/AssistantMarkdown.module.css
@@ -1,14 +1,22 @@
-/* Assistant flow body: full-width narration (figma 16/28), block gap 16. */
+/* Assistant flow body: full-width narration (figma 16/28), block gap 16.
+   IconActions sit below the body with an explicit 16px top margin (figma
+   43:32997) — separate from the body's internal gap so the footer spacing
+   stays fixed when the body is a single block. */

 .root {
  display: flex;
  flex-direction: column;
-  gap: 16px;
  font-size: 16px;
  line-height: 28px;
  color: var(--dsw-alias-label-primary);
 }

+.body {
+  display: flex;
+  flex-direction: column;
+  gap: 16px;
+}
+
 /* Interrupted-turn terminal marker: quiet inline tag, no animation. */
 .stopped {
  align-self: flex-start;
@@ -19,3 +27,18 @@
  font-size: 11px;
  line-height: 18px;
 }
+
+/* Finalized footer offset (figma 43:32997); chrome lives in MessageIconActions. */
+.actions {
+  margin-top: 16px;
+  /* Optical align with 28px icon hit targets that pad 6px past the glyph. */
+  margin-left: -6px;
+}
+
+/* Hover-capable pointers: reveal shared actions on root hover/focus. */
+@media (hover: hover) {
+  .root:hover .actions,
+  .root:focus-within .actions {
+    opacity: 1;
+  }
+}
--- a/packages/client/ui-conversation/src/client/chat/AssistantMarkdown.tsx
+++ b/packages/client/ui-conversation/src/client/chat/AssistantMarkdown.tsx
@@ -4,10 +4,14 @@
 // view groups them into tool rows through its keyed toolview slot (figma
 // step-summary flow). Shared by finalized nodes and the streaming partial;
 // the turn-level loading dots live in the chat view's tail, not here.
+// Finalized nodes append IconActions (copy / branch / clock) once streaming ends.

 import { memo } from 'react'
 import type { AssistantBlock } from '@deepseek-ai/dsh-client-runtime/client'
-import { IconThinkOutline14, JsonBlock, MarkdownText } from '@deepseek-ai/dsh-client-ui-primitives'
+import {
+  IconThinkOutline14, JsonBlock, MarkdownText,
+} from '@deepseek-ai/dsh-client-ui-primitives'
+import { MessageIconActions } from './MessageIconActions.tsx'
 import { ToolRow } from './ToolRow.tsx'
 import css from './AssistantMarkdown.module.css'

@@ -16,6 +20,8 @@ export interface AssistantMarkdownProps {
  streaming: boolean
  /** Frozen partial of an aborted turn: rendered with a 已停止 marker. */
  interrupted?: boolean | undefined
+  /** Unix epoch ms for the finalized IconActions clock; omitted while streaming. */
+  time?: number | undefined
 }

 function firstLine(text: string): string {
@@ -23,6 +29,15 @@ function firstLine(text: string): string {
  return nl === -1 ? text : text.slice(0, nl)
 }

+/** Joined text blocks for the copy action (reasoning / tool heads stay out). */
+function copyText(blocks: readonly AssistantBlock[]): string {
+  const parts: string[] = []
+  for (const block of blocks) {
+    if (block.kind === 'text') parts.push(block.text)
+  }
+  return parts.join('')
+}
+
 /** Reasoning block as the Think variant summary row (figma 39:28304). */
 function ThinkRow({ text, running }: { text: string; running: boolean }) {
  return (
@@ -38,7 +53,9 @@ function ThinkRow({ text, running }: { text: string; running: boolean }) {
  )
 }

-export const AssistantMarkdown = memo(function AssistantMarkdown({ blocks, streaming, interrupted }: AssistantMarkdownProps) {
+export const AssistantMarkdown = memo(function AssistantMarkdown({
+  blocks, streaming, interrupted, time,
+}: AssistantMarkdownProps) {
  const last = blocks.length - 1
  // Tool-call heads render as tool rows in the chat view's grouping pass, so
  // a node that is only those heads (or empty) would paint an empty root
@@ -47,18 +64,30 @@ export const AssistantMarkdown = memo(function AssistantMarkdown({ blocks, strea
    || interrupted === true
    || blocks.some(block => block.kind !== 'tool-call')
  if (!hasVisible) return null
+  // Footer only after the turn settles with a known event time; streaming omits it.
+  const showActions = !streaming && time !== undefined
  return (
    <div className={css.root} data-streaming={streaming || undefined}>
-      {blocks.map((block, i) => {
-        switch (block.kind) {
-          case 'text': return <MarkdownText key={i} text={block.text} streaming={streaming} />
-          case 'reasoning': return <ThinkRow key={i} text={block.text} running={streaming && i === last} />
-          // Grouped into tool rows by ChatView; hasVisible above skips an empty shell.
-          case 'tool-call': return null
-          default: return <JsonBlock key={i} label="未知内容块" payload={block.block} />
-        }
-      })}
-      {interrupted && <span className={css.stopped}>已停止</span>}
+      <div className={css.body}>
+        {blocks.map((block, i) => {
+          switch (block.kind) {
+            case 'text': return <MarkdownText key={i} text={block.text} streaming={streaming} />
+            case 'reasoning': return <ThinkRow key={i} text={block.text} running={streaming && i === last} />
+            // Grouped into tool rows by ChatView; hasVisible above skips an empty shell.
+            case 'tool-call': return null
+            default: return <JsonBlock key={i} label="未知内容块" payload={block.block} />
+          }
+        })}
+        {interrupted && <span className={css.stopped}>已停止</span>}
+      </div>
+      {showActions && (
+        <MessageIconActions
+          text={copyText(blocks)}
+          time={time}
+          clock="end"
+          className={css.actions}
+        />
+      )}
    </div>
  )
 })
--- a/packages/client/ui-conversation/src/client/chat/ChatView.tsx
+++ b/packages/client/ui-conversation/src/client/chat/ChatView.tsx
@@ -332,7 +332,15 @@ export function ChatView({
    }
    const node: ConversationNode = item.node
    if (node.kind === 'assistant') {
-      return <AssistantMarkdown key={item.key} blocks={node.blocks} streaming={false} interrupted={node.interrupted} />
+      return (
+        <AssistantMarkdown
+          key={item.key}
+          blocks={node.blocks}
+          streaming={false}
+          interrupted={node.interrupted}
+          time={node.time}
+        />
+      )
    }
    if (node.kind === 'command') {
      return <CommandRow key={item.key} renderSlot={renderSlot} node={node} />
--- a/packages/client/ui-conversation/src/client/chat/MessageIconActions.module.css
+++ b/packages/client/ui-conversation/src/client/chat/MessageIconActions.module.css
@@ -0,0 +1,53 @@
+/* Shared message IconActions row (user + assistant). Parent modules own
+   hover-reveal selectors and layout offsets via the composed className. */
+
+.actions {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  height: 28px;
+}
+
+/* Clock before icons (user figma 388:20051) / after (assistant 43:32997). */
+.timeStart {
+  padding-right: 12px;
+  font-size: 14px;
+  line-height: 24px;
+  color: var(--dsw-alias-label-tertiary);
+  white-space: nowrap;
+}
+
+.timeEnd {
+  padding-left: 12px;
+  font-size: 14px;
+  line-height: 24px;
+  color: var(--dsw-alias-label-tertiary);
+  white-space: nowrap;
+}
+
+/* Hover-capable pointers: hide until a parent hover/focus rule reveals. */
+@media (hover: hover) {
+  .actions {
+    opacity: 0;
+    transition: opacity var(--ds-transition-duration) var(--ds-ease-in-out);
+  }
+}
+
+.action {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  width: 28px;
+  height: 28px;
+  padding: 6px;
+  border: none;
+  border-radius: 28px;
+  background: transparent;
+  color: var(--dsw-alias-label-tertiary);
+  cursor: pointer;
+}
+
+.action:hover {
+  background: var(--dsw-alias-interactive-bg-hover);
+  color: var(--dsw-alias-label-secondary);
+}
--- a/packages/client/ui-conversation/src/client/chat/MessageIconActions.tsx
+++ b/packages/client/ui-conversation/src/client/chat/MessageIconActions.tsx
@@ -0,0 +1,65 @@
+// Shared IconActions chrome for user and assistant messages: copy / branch
+// live (branch still a stub), date-aware clock, optional edit stub.
+
+import { useCallback } from 'react'
+import {
+  IconBranchOutline16, IconCopyOutline16, IconEditOutline16, Tooltip,
+} from '@deepseek-ai/dsh-client-ui-primitives'
+import { formatMessageClock, writeClipboard } from './message-chrome.ts'
+import { useCalendarDay } from './use-calendar-day.ts'
+import css from './MessageIconActions.module.css'
+
+export interface MessageIconActionsProps {
+  /** Plain text the copy action writes. */
+  text: string
+  /** Unix epoch ms for the clock label. */
+  time: number
+  /** Clock before icons (user) or after (assistant). */
+  clock: 'start' | 'end'
+  /** When true, append the stub edit control (user bubble). */
+  edit?: boolean | undefined
+  /** Parent layout / hover-reveal class composed onto the actions row. */
+  className?: string | undefined
+}
+
+/**
+ * Copy / branch (/ clock) IconActions row shared by user and assistant chrome.
+ * @param props - Copy text, event time, clock side, optional edit, className.
+ * @returns The actions row element.
+ */
+export function MessageIconActions({
+  text, time, clock, edit, className,
+}: MessageIconActionsProps) {
+  const day = useCalendarDay()
+  const onCopy = useCallback(() => {
+    void writeClipboard(text)
+  }, [text])
+  const clockEl = (
+    <span className={clock === 'start' ? css.timeStart : css.timeEnd}>
+      {formatMessageClock(time, day)}
+    </span>
+  )
+  return (
+    <div className={className === undefined ? css.actions : `${css.actions} ${className}`}>
+      {clock === 'start' ? clockEl : null}
+      <Tooltip label="复制" side="bottom">
+        <button type="button" className={css.action} aria-label="复制" onClick={onCopy}>
+          <IconCopyOutline16 />
+        </button>
+      </Tooltip>
+      <Tooltip label="在新对话中分支" side="bottom">
+        <button type="button" className={css.action} aria-label="在新对话中分支">
+          <IconBranchOutline16 />
+        </button>
+      </Tooltip>
+      {edit === true && (
+        <Tooltip label="编辑" side="bottom">
+          <button type="button" className={css.action} aria-label="编辑">
+            <IconEditOutline16 />
+          </button>
+        </Tooltip>
+      )}
+      {clock === 'end' ? clockEl : null}
+    </div>
+  )
+}
--- a/packages/client/ui-conversation/src/client/chat/MessageItem.module.css
+++ b/packages/client/ui-conversation/src/client/chat/MessageItem.module.css
@@ -20,46 +20,14 @@
  color: var(--dsw-alias-label-primary);
 }

-.actions {
-  display: flex;
-  align-items: center;
-  gap: 10px;
-  height: 28px;
-}
-
-/* Hover-capable pointers: hide until the row is hovered/focused. Touch /
-   hover:none keeps actions visible (opacity:0 still hit-tests). */
+/* Hover-capable pointers: reveal shared MessageIconActions on row hover/focus. */
@media (hover: hover) {
-  .actions {
-    opacity: 0;
-    transition: opacity var(--ds-transition-duration) var(--ds-ease-in-out);
-  }
-
  .userRow:hover .actions,
  .userRow:focus-within .actions {
    opacity: 1;
  }
 }

-.action {
-  display: inline-flex;
-  align-items: center;
-  justify-content: center;
-  width: 28px;
-  height: 28px;
-  padding: 6px;
-  border: none;
-  border-radius: 28px;
-  background: transparent;
-  color: var(--dsw-alias-label-tertiary);
-  cursor: pointer;
-}
-
-.action:hover {
-  background: var(--dsw-alias-interactive-bg-hover);
-  color: var(--dsw-alias-label-secondary);
-}
-
 .badge {
  display: inline-block;
  margin-bottom: 4px;
--- a/packages/client/ui-conversation/src/client/chat/MessageItem.tsx
+++ b/packages/client/ui-conversation/src/client/chat/MessageItem.tsx
@@ -1,18 +1,16 @@
 // MessageItem: the four simple node kinds — user bubble (right-aligned, with
-// copy / branch / edit IconActions), steering (badged bubble), context
+// clock + copy / branch / edit IconActions), steering (badged bubble), context
 // injection and unknown-surface JSON rows. Props are frozen node slices off
 // the snapshot cache; memo holds across streaming because unchanged nodes
 // keep their references.

-import { memo, useCallback } from 'react'
+import { memo } from 'react'
 import type { ReactNode } from 'react'
 import type {
  ContextMessageNode, SteeringMessageNode, UnknownSurfaceNode, UserMessageNode,
 } from '@deepseek-ai/dsh-client-runtime/client'
-import {
-  IconBranchOutline16, IconCopyOutline16, IconEditOutline16,
-  JsonBlock, MessageText, Tooltip,
-} from '@deepseek-ai/dsh-client-ui-primitives'
+import { JsonBlock, MessageText } from '@deepseek-ai/dsh-client-ui-primitives'
+import { MessageIconActions } from './MessageIconActions.tsx'
 import css from './MessageItem.module.css'

 export interface MessageItemProps {
@@ -30,42 +28,6 @@ function contentText(content: readonly unknown[]): { text: string; rest: unknown
  return { text: texts.join(''), rest }
 }

-/** Best-effort clipboard write; rejections stay swallowed (no success chrome). */
-async function writeClipboard(text: string): Promise<void> {
-  // lib.dom types clipboard non-optional, but insecure contexts omit it —
-  // that runtime gap is exactly what this guard detects.
-  /* eslint-disable-next-line @typescript-eslint/no-unnecessary-condition */
-  if (navigator.clipboard?.writeText) {
-    try {
-      await navigator.clipboard.writeText(text)
-    } catch {
-      // Denied permissions / iframe policy.
-    }
-    return
-  }
-  // execCommand('copy') is the only clipboard fallback where the async API
-  // is missing (insecure contexts); deprecated but deliberately retained.
-  /* eslint-disable @typescript-eslint/no-deprecated */
-  const exec = typeof document.execCommand === 'function'
-    ? document.execCommand.bind(document)
-    : undefined
-  if (exec === undefined) return
-  const el = document.createElement('textarea')
-  el.value = text
-  el.setAttribute('readonly', '')
-  el.style.position = 'fixed'
-  el.style.left = '-9999px'
-  document.body.appendChild(el)
-  el.select()
-  try {
-    exec('copy')
-  } catch {
-    // Clipboard unavailable; the button stays idle.
-  }
-  /* eslint-enable @typescript-eslint/no-deprecated */
-  el.remove()
-}
-
 /**
 * Display projection of reference forms in a user bubble (free geometry — no
 * textarea alignment constraint here); everything else stays plain text. The
@@ -98,32 +60,6 @@ function projectUserText(text: string): ReactNode {
  return <>{parts}</>
 }

-/** User-bubble IconActions (figma 659:38820): copy is live; branch/edit are chrome stubs. */
-function UserActions({ text }: { text: string }) {
-  const onCopy = useCallback(() => {
-    void writeClipboard(text)
-  }, [text])
-  return (
-    <div className={css.actions}>
-      <Tooltip label="复制" side="bottom">
-        <button type="button" className={css.action} aria-label="复制" onClick={onCopy}>
-          <IconCopyOutline16 />
-        </button>
-      </Tooltip>
-      <Tooltip label="在新对话中分支" side="bottom">
-        <button type="button" className={css.action} aria-label="在新对话中分支">
-          <IconBranchOutline16 />
-        </button>
-      </Tooltip>
-      <Tooltip label="编辑" side="bottom">
-        <button type="button" className={css.action} aria-label="编辑">
-          <IconEditOutline16 />
-        </button>
-      </Tooltip>
-    </div>
-  )
-}
-
 export const MessageItem = memo(function MessageItem({ node }: MessageItemProps) {
  switch (node.kind) {
    case 'user': {
@@ -134,7 +70,13 @@ export const MessageItem = memo(function MessageItem({ node }: MessageItemProps)
            {projectUserText(text)}
            {rest.map((block, i) => <JsonBlock key={i} label="附加内容块" payload={block} />)}
          </div>
-          <UserActions text={text} />
+          <MessageIconActions
+            text={text}
+            time={node.time}
+            clock="start"
+            edit
+            className={css.actions}
+          />
        </div>
      )
    }
--- a/packages/client/ui-conversation/src/client/chat/message-chrome.ts
+++ b/packages/client/ui-conversation/src/client/chat/message-chrome.ts
@@ -0,0 +1,91 @@
+// Shared chrome helpers for user/assistant IconActions rows: clipboard write
+// and the compact date+clock label from a session-event epoch.
+
+/**
+ * Best-effort clipboard write; rejections stay swallowed (no success chrome).
+ * @param text - Plain text to place on the clipboard.
+ */
+export async function writeClipboard(text: string): Promise<void> {
+  // lib.dom types clipboard non-optional, but insecure contexts omit it —
+  // that runtime gap is exactly what this guard detects.
+  /* eslint-disable-next-line @typescript-eslint/no-unnecessary-condition */
+  if (navigator.clipboard?.writeText) {
+    try {
+      await navigator.clipboard.writeText(text)
+    } catch {
+      // Denied permissions / iframe policy.
+    }
+    return
+  }
+  // execCommand('copy') is the only clipboard fallback where the async API
+  // is missing (insecure contexts); deprecated but deliberately retained.
+  /* eslint-disable @typescript-eslint/no-deprecated */
+  const exec = typeof document.execCommand === 'function'
+    ? document.execCommand.bind(document)
+    : undefined
+  if (exec === undefined) return
+  const el = document.createElement('textarea')
+  el.value = text
+  el.setAttribute('readonly', '')
+  el.style.position = 'fixed'
+  el.style.left = '-9999px'
+  document.body.appendChild(el)
+  el.select()
+  try {
+    exec('copy')
+  } catch {
+    // Clipboard unavailable; the button stays idle.
+  }
+  /* eslint-enable @typescript-eslint/no-deprecated */
+  el.remove()
+}
+
+function pad2(n: number): string {
+  return String(n).padStart(2, '0')
+}
+
+/**
+ * Local calendar-day epoch (ms at local midnight) for an instant.
+ * @param ms - Unix epoch ms.
+ * @returns Midnight of that local calendar day.
+ */
+export function startOfLocalDay(ms: number): number {
+  const d = new Date(ms)
+  d.setHours(0, 0, 0, 0)
+  return d.getTime()
+}
+
+/**
+ * Delay until the next local midnight after `ms` (at least 1ms).
+ * @param ms - Unix epoch ms.
+ * @returns Milliseconds until the following local midnight.
+ */
+export function msUntilNextLocalMidnight(ms: number): number {
+  const next = new Date(ms)
+  next.setHours(24, 0, 0, 0)
+  return Math.max(next.getTime() - ms, 1)
+}
+
+/**
+ * Compact local timestamp for message IconActions.
+ * Same calendar day → `HH:mm`; earlier this year → `M月D日 HH:mm`;
+ * other years → `YYYY年M月D日 HH:mm`.
+ * @param time - Unix epoch ms from the source session event.
+ * @param now - Reference instant for the day/year cut (defaults to wall clock).
+ * @returns Date-aware clock string (24-hour, zero-padded time).
+ */
+export function formatMessageClock(time: number, now: number = Date.now()): string {
+  const d = new Date(time)
+  const n = new Date(now)
+  const clock = `${pad2(d.getHours())}:${pad2(d.getMinutes())}`
+  if (
+    d.getFullYear() === n.getFullYear()
+    && d.getMonth() === n.getMonth()
+    && d.getDate() === n.getDate()
+  ) {
+    return clock
+  }
+  const md = `${d.getMonth() + 1}月${d.getDate()}日`
+  if (d.getFullYear() === n.getFullYear()) return `${md} ${clock}`
+  return `${d.getFullYear()}年${md} ${clock}`
+}
--- a/packages/client/ui-conversation/src/client/chat/use-calendar-day.ts
+++ b/packages/client/ui-conversation/src/client/chat/use-calendar-day.ts
@@ -0,0 +1,25 @@
+// Component-local calendar-day tick: memoized message rows keep stable props
+// across midnight, so the IconActions clock needs a local day seat that
+// re-fires at the next local midnight without reaching for framework hooks.
+
+import { useEffect, useState } from 'react'
+import { msUntilNextLocalMidnight, startOfLocalDay } from './message-chrome.ts'
+
+/**
+ * Local calendar-day epoch that advances at each local midnight.
+ * @returns Midnight ms for the current local day; updates after the boundary.
+ */
+export function useCalendarDay(): number {
+  const [day, setDay] = useState(() => startOfLocalDay(Date.now()))
+  useEffect(() => {
+    let timer: ReturnType<typeof setTimeout>
+    const arm = (): void => {
+      const now = Date.now()
+      setDay(startOfLocalDay(now))
+      timer = setTimeout(arm, msUntilNextLocalMidnight(now))
+    }
+    timer = setTimeout(arm, msUntilNextLocalMidnight(Date.now()))
+    return () => { clearTimeout(timer) }
+  }, [])
+  return day
+}
--- a/packages/client/ui-conversation/tests/chat-branch-tails.spec.tsx
+++ b/packages/client/ui-conversation/tests/chat-branch-tails.spec.tsx
@@ -5,9 +5,12 @@
 // with the keyed-slot machinery specs since the tool ring dissolved into
 // renderSlot.)

-import { afterEach, describe, expect, it, vi } from 'vitest'
-import { cleanup, fireEvent, render, screen } from '@testing-library/react'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import { act, cleanup, fireEvent, render, screen } from '@testing-library/react'
 import { bindSnapshotSelector } from '@deepseek-ai/dsh-client-web-react'
+import {
+  formatMessageClock, msUntilNextLocalMidnight, startOfLocalDay,
+} from '../src/client/chat/message-chrome.ts'
 import { MessageItem } from '../src/client/chat/MessageItem.tsx'
 import { AssistantMarkdown } from '../src/client/chat/AssistantMarkdown.tsx'
 import { StatsLine, type StatsLineProps } from '../src/client/chat/StatsLine.tsx'
@@ -15,19 +18,24 @@ import { StatsLine, type StatsLineProps } from '../src/client/chat/StatsLine.tsx
 afterEach(cleanup)

 describe('MessageItem arms', () => {
-  it('user bubbles expose copy / branch / edit actions; copy writes the text', () => {
+  it('user bubbles expose clock / copy / branch / edit; copy writes the text', () => {
    const writeText = vi.fn().mockResolvedValue(undefined)
    Object.defineProperty(navigator, 'clipboard', {
      configurable: true,
      value: { writeText },
    })
+    // Same-day clock: construct "today at 14:24" so the label stays `HH:mm`.
+    const now = new Date()
+    const time = new Date(now.getFullYear(), now.getMonth(), now.getDate(), 14, 24).getTime()
    render(
      <MessageItem node={{
-        kind: 'user', seq: 1,
+        kind: 'user', seq: 1, time,
        content: [{ type: 'text', text: 'hello bubble' }] as never,
-      } as never}
+        source: null,
+      }}
      />,
    )
+    expect(screen.getByText('14:24')).toBeTruthy()
    expect(screen.getByRole('button', { name: '复制' })).toBeTruthy()
    expect(screen.getByRole('button', { name: '在新对话中分支' })).toBeTruthy()
    expect(screen.getByRole('button', { name: '编辑' })).toBeTruthy()
@@ -47,9 +55,10 @@ describe('MessageItem arms', () => {
    })
    render(
      <MessageItem node={{
-        kind: 'user', seq: 1,
+        kind: 'user', seq: 1, time: 1_000,
        content: [{ type: 'text', text: 'fallback body' }] as never,
-      } as never}
+        source: null,
+      }}
      />,
    )
    fireEvent.click(screen.getByRole('button', { name: '复制' }))
@@ -69,9 +78,10 @@ describe('MessageItem arms', () => {
    })
    render(
      <MessageItem node={{
-        kind: 'user', seq: 1,
+        kind: 'user', seq: 1, time: 1_000,
        content: [{ type: 'text', text: 'quiet' }] as never,
-      } as never}
+        source: null,
+      }}
      />,
    )
    fireEvent.click(screen.getByRole('button', { name: '复制' }))
@@ -109,6 +119,56 @@ describe('MessageItem arms', () => {
  })
 })

+describe('formatMessageClock', () => {
+  const now = new Date(2026, 6, 29, 10, 0).getTime()
+
+  it('keeps HH:mm on the same calendar day', () => {
+    expect(formatMessageClock(new Date(2026, 6, 29, 14, 24).getTime(), now)).toBe('14:24')
+  })
+
+  it('prefixes month and day across days in the same year', () => {
+    expect(formatMessageClock(new Date(2026, 0, 1, 14, 24).getTime(), now)).toBe('1月1日 14:24')
+  })
+
+  it('prefixes year, month, and day across years', () => {
+    expect(formatMessageClock(new Date(2025, 11, 31, 9, 5).getTime(), now)).toBe('2025年12月31日 09:05')
+  })
+
+  it('arms the next local midnight from an in-day instant', () => {
+    const noon = new Date(2026, 6, 29, 12, 0).getTime()
+    expect(startOfLocalDay(noon)).toBe(new Date(2026, 6, 29).getTime())
+    expect(msUntilNextLocalMidnight(noon)).toBe(12 * 3_600_000)
+  })
+})
+
+describe('useCalendarDay boundary refresh', () => {
+  beforeEach(() => {
+    vi.useFakeTimers()
+  })
+  afterEach(() => {
+    vi.useRealTimers()
+  })
+
+  it('widens a same-day user clock after local midnight', () => {
+    const dayStart = new Date(2026, 6, 29, 23, 50).getTime()
+    vi.setSystemTime(dayStart)
+    const time = new Date(2026, 6, 29, 14, 24).getTime()
+    render(
+      <MessageItem node={{
+        kind: 'user', seq: 1, time,
+        content: [{ type: 'text', text: 'night bubble' }] as never,
+        source: null,
+      }}
+      />,
+    )
+    expect(screen.getByText('14:24')).toBeTruthy()
+    act(() => {
+      vi.advanceTimersByTime(msUntilNextLocalMidnight(dayStart) + 1)
+    })
+    expect(screen.getByText('7月29日 14:24')).toBeTruthy()
+  })
+})
+
 describe('small branch tails', () => {
  it('AssistantMarkdown single-line reasoning summary skips the newline cut', () => {
    const view = render(
@@ -117,6 +177,35 @@ describe('small branch tails', () => {
    expect(view.getByText('one-liner')).toBeTruthy()
  })

+  it('finalized assistant messages expose copy / branch / clock after the body; streaming omits them', () => {
+    const writeText = vi.fn().mockResolvedValue(undefined)
+    Object.defineProperty(navigator, 'clipboard', {
+      configurable: true,
+      value: { writeText },
+    })
+    const now = new Date()
+    const time = new Date(now.getFullYear(), now.getMonth(), now.getDate(), 14, 24).getTime()
+    const settled = render(
+      <AssistantMarkdown
+        blocks={[{ kind: 'text', text: 'answer body' }, { kind: 'reasoning', text: 'hidden' }]}
+        streaming={false}
+        time={time}
+      />,
+    )
+    expect(settled.getByText('14:24')).toBeTruthy()
+    expect(settled.getByRole('button', { name: '复制' })).toBeTruthy()
+    expect(settled.getByRole('button', { name: '在新对话中分支' })).toBeTruthy()
+    fireEvent.click(settled.getByRole('button', { name: '复制' }))
+    expect(writeText).toHaveBeenCalledWith('answer body')
+    settled.unmount()
+
+    const streaming = render(
+      <AssistantMarkdown blocks={[{ kind: 'text', text: 'partial' }]} streaming time={time} />,
+    )
+    expect(streaming.queryByRole('button', { name: '复制' })).toBeNull()
+    expect(streaming.queryByText('14:24')).toBeNull()
+  })
+
  it('StatsLine omits the cache-hit segment when no input accounting exists at all', () => {
    const snap = {
      nodes: [{ kind: 'assistant', seq: 1, turn: 1, step: 1, blocks: [], usage: { outputTokens: 10 } }],
--- a/packages/client/ui-layout/README.i18n.yaml
+++ b/packages/client/ui-layout/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-layout/README.md
-README.md: 26e909b96412985792eeae72d51a2ab2a315c943
-README.zh.md: 2e5799fd32c41328f8ca8b9e1a439fbccb3cdba2
+README.md: 9354f4b79f7b1af7d8a20a295e77913ff443c2e4
+README.zh.md: c949236557e7eb3eed0c698566fb5aa9e9cdd18a
--- a/packages/client/ui-layout/README.md
+++ b/packages/client/ui-layout/README.md
@@ -4,7 +4,7 @@ English | [中文](README.zh.md)

 Shell plugin: three-column AppFrame (drag handles and concession chain) plus the `ctx.layout` panel-geometry service; it registers into the runtime-owned `root` slot and declares `sidebar`, `conversation`, `details`, and `conversation.empty`. The sidebar is fixed-width (only details shrinks, then auto-closes); a closed sidebar retains a 56px control rail while details closes to zero width. The package also seats the theme presenter: it consumes resolved `ctx.theme` snapshots and projects them onto the document (`html { color-scheme }` for native UA chrome, `body[data-ds-dark-theme]` from the active color scheme, plus the theme's alias tokens as inline variables on body).

-AppFrame reads the runtime Session projection: `baselinesReady` selects loading, a page-local `SessionListState.intent` selects the empty composer, and a connected Session renders through `SessionProvider`. The conversation and empty-state owner shares are empty; each registrant obtains business data from standard hooks and actions from its own inject face. The sidebar owner share contains only `collapsed` and `width`; navigation actions belong to sidebar's own injected service face.
+AppFrame always mounts the conversation and details columns; a connected Session renders through `SessionProvider`. The transient layout store starts both panels at their default widths and never reads or writes `localStorage`. Hero and other unselected states derive a zero rendered details width without changing that stored preference. AppFrame retains the last non-blank Session id across those states: the first Session opens at the default width, returning to the same Session restores its unchanged width, and selecting a different Session closes details before paint. The conversation owner share is empty, while the sidebar owner share contains only `collapsed` and `width`; registrants obtain business data from standard hooks and actions from their own inject faces.

 The `/client` export surface is the plugin body (`apply`/`inject`), `LayoutService`, and the four owner-share interfaces. AppFrame, the panel store, and the concession solver remain package-internal; tests import internals through `/src`.

@@ -18,6 +18,6 @@ None; this package neither assembles nor sends a provider request.

 ## Known Limitations and Deferred Work

- **Details open/width state is global** — it does not follow the session (arbitrated for P-I); the per-session keyed upgrade slot is reserved.
- **Concession-chain auto-close derives a zero width without touching the persisted open flag** — the panel restores itself when the window widens; consumers must not read `details.open` as the rendered truth.
+- **Panel geometry is transient** — reload restores both panels to their defaults; switching between distinct Session ids closes details and forgets its dragged width, while unselected surfaces render details at zero width without modifying geometry.
+- **Concession-chain auto-close derives a zero width without touching the preferred width** — the panel restores itself when the window widens; consumers must not read the stored details width as the rendered truth.
 - **Scroll anchoring during squeeze reflow is not implemented** — deferred with the virtualized-list project.
--- a/packages/client/ui-layout/README.zh.md
+++ b/packages/client/ui-layout/README.zh.md
@@ -4,7 +4,7 @@

 外壳插件：三栏 AppFrame（拖动手柄与让步链）加 `ctx.layout` 面板几何服务；它注册到运行时拥有的 `root` slot，并声明 `sidebar`、`conversation`、`details` 和 `conversation.empty`。侧边栏宽度固定（只会收缩详情栏，然后将其自动关闭）；关闭的侧边栏仍保留 56px 控制轨道，详情栏则关闭到零宽度。该包还提供主题呈现器：它消费解析后的 `ctx.theme` 快照，并将其投影到 document（用 `html { color-scheme }` 驱动原生 UA 控件，依据当前配色方案设置 `body[data-ds-dark-theme]`，并将主题的别名 token 设为 body 上的内联变量）。

-AppFrame 读取运行时 Session 投影：`baselinesReady` 选择加载状态，页面局部的 `SessionListState.intent` 选择空白编辑器，已连接 Session 则通过 `SessionProvider` 渲染。会话及空状态的 owner share 为空；每个注册方通过标准 hook 获取业务数据，并从自身的 inject 表层获取操作。侧边栏 owner share 只包含 `collapsed` 和 `width`；导航操作属于侧边栏自身注入的服务表层。
+AppFrame 始终挂载会话栏和详情栏；已连接 Session 通过 `SessionProvider` 渲染。布局 store 是瞬时状态，两个面板均以默认宽度启动，且从不读写 `localStorage`。hero 和其他未选中状态会将详情栏的渲染宽度派生为零，但不会改变存储的首选宽度。AppFrame 会跨越这些状态保留最后一个非 blank 会话 id：首个会话以默认宽度打开；返回同一会话时恢复其未改变的宽度；选择不同会话时，详情栏会在绘制前关闭。会话 owner share 为空，侧边栏 owner share 只包含 `collapsed` 和 `width`；注册方通过标准钩子获取业务数据，并从各自的 inject 表层获取操作。

 `/client` 导出表层包含插件主体（`apply`／`inject`）、`LayoutService` 和四个 owner-share 接口。AppFrame、面板 store 与让步求解器仍属于包内部；测试通过 `/src` 导入内部实现。

@@ -18,6 +18,6 @@ AppFrame 读取运行时 Session 投影：`baselinesReady` 选择加载状态，

 ## 已知限制与暂缓事项

- **详情栏打开／宽度状态是全局状态**：它不会随会话变化（P-I 已裁定）；为逐会话键控升级预留了 slot。
- **让步链自动关闭通过推导零宽度实现，不会改动持久化的打开标志**：窗口变宽时面板会自行恢复；消费方禁止把 `details.open` 当作实际渲染状态。
+- **面板几何信息是瞬时状态**：重新加载会将两个面板恢复为默认值；在不同会话 id 之间切换会关闭详情栏，并忘记拖动后的宽度，而未选中表面会以零宽度渲染详情栏，但不会修改几何信息。
+- **让步链自动关闭通过推导零宽度实现，不会改动首选宽度**：窗口变宽时面板会自行恢复；消费方禁止把 store 中的详情宽度当作实际渲染状态。
 - **挤压重排期间尚未实现滚动锚定**：与虚拟化列表项目一并暂缓。
--- a/packages/client/ui-layout/src/client/AppFrame.tsx
+++ b/packages/client/ui-layout/src/client/AppFrame.tsx
@@ -10,7 +10,7 @@
 * through the three framework shares — zero cordis or framework imports,
 * zero self-made hooks.
 */
-import { useCallback, useEffect, useRef, useState } from 'react'
+import { useCallback, useEffect, useLayoutEffect, useRef, useState } from 'react'
 import type { ReactNode } from 'react'
 import type { PropsRenderSlots, PropsRuntime, PropsStore } from '@deepseek-ai/dsh-client-ui-slots'
 import { computeColumns } from './columns.ts'
@@ -86,13 +86,27 @@ function DragHandle(props: { side: 'sidebar' | 'details'; left: number; onStart:
 /** The three-column frame (see module doc). */
 export function AppFrame({
  useStore,
+  useSessions,
  actions,
  renderSlot,
 }: AppFrameProps) {
  const panels = useStore(s => s)
+  const detailsSession = useSessions((s) => {
+    const current = s.current
+    return current !== undefined && s.byId[current]?.blank === false ? current : undefined
+  })
  const frameRef = useRef<HTMLDivElement | null>(null)
  const [viewport, setViewport] = useState(() => window.innerWidth)

+  const lastSession = useRef(detailsSession)
+  useLayoutEffect(() => {
+    if (detailsSession === undefined) return
+    if (lastSession.current !== undefined && lastSession.current !== detailsSession) {
+      actions.closeDetails()
+    }
+    lastSession.current = detailsSession
+  }, [actions, detailsSession])
+
  // Track the frame's own box (not the window): rAF-throttled ResizeObserver.
  useEffect(() => {
    const el = frameRef.current
@@ -113,12 +127,12 @@ export function AppFrame({
    }
  }, [])

-  const cols = computeColumns(viewport, panels.sidebar, panels.details)
+  const cols = computeColumns(viewport, panels.sidebar, detailsSession === undefined ? 0 : panels.details)
  const colsRef = useRef(cols)
  colsRef.current = cols

  // The drag base is the rendered width captured at drag start (grabbing a
-  // concession-clamped panel must not jump back to the persisted preference);
+  // concession-clamped panel must not jump back to the stored preference);
  // it stays frozen for the whole gesture so dx deltas do not compound.
  const sidebarBase = useRef(0)
  const detailsBase = useRef(0)
--- a/packages/client/ui-layout/src/client/columns.ts
+++ b/packages/client/ui-layout/src/client/columns.ts
@@ -1,7 +1,7 @@
 /**
 * Pure concession-chain column solver for the three-column AppFrame.
 * Chain order is fixed by contract: keep center >= CENTER_MIN by shrinking
- * details, then auto-closing it (derived zero width — persisted width
+ * details, then auto-closing it (derived zero width — preferred width
 * preferences are never rewritten, so widening the window restores them).
 * The sidebar never concedes: its rendered width is always the drag
 * preference (or the collapsed rail), and center absorbs any remaining
@@ -45,8 +45,8 @@ export function clampWidth(px: number, min: number, max: number): number {
 /**
 * Solve the three column widths for one viewport frame. Pure: no hysteresis —
 * the output is a function of (viewport, preferences) only, so recovery on
- * re-widening is automatic. Preferences re-clamp here because they cross a
- * durable boundary (localStorage rehydration may carry stale ranges).
+ * re-widening is automatic. Preferences re-clamp here because they cross the
+ * store boundary and callers may still supply stale ranges.
 * @param viewport - available frame width in px.
 * @param sidebar - sidebar width preference in px (0 = closed).
 * @param details - details width preference in px (0 = closed).
--- a/packages/client/ui-layout/src/client/stores.ts
+++ b/packages/client/ui-layout/src/client/stores.ts
@@ -1,7 +1,7 @@
 /**
- * The root entry's layout store: panel geometry as plain widths in px
- * (0 = closed), persisted across reloads. Module level exports the factory
- * only — a module-level handle would pin the store's identity in the module
+ * The root entry's transient layout store: panel geometry as plain widths in
+ * px (0 = closed). Module level exports the factory only — a module-level
+ * handle would pin the store's identity in the module
 * cache (a de-facto singleton surviving plugin reloads). register() receives
 * the factory (exclusive use: the framework instantiates per entry), AppFrame
 * derives its PropsStore share from the return type, and the service face
@@ -29,17 +29,16 @@ type LayoutActions = {
 }

 /**
- * Create the layout panel store handle. The persisted preference IS the
- * width, so closing a panel forgets its drag width — reopening restores the
- * contract default. Actions are the complete write set: drag writes clamp
+ * Create the layout panel store handle. The preference IS the width, so
+ * closing a panel forgets its drag width — reopening restores the contract
+ * default. Actions are the complete write set: drag writes clamp
 * into the panel's contract range and never cross the open/closed line;
 * open/close transitions write 0 / the default explicitly.
 * @returns the store handle (spec + type + identity + factory in one).
 */
 export function createLayoutStore(): EngineStoreHandle<LayoutState, LayoutActions>  {
  const handle = defineStore({
-    init: (): LayoutState => ({ sidebar: SIDEBAR_DEFAULT, details: 0 }),
-    persist: 'dsh.layout.panels',
+    init: (): LayoutState => ({ sidebar: SIDEBAR_DEFAULT, details: DETAILS_DEFAULT }),
    actions: {
      setSidebar: (d, px: number) => { d.sidebar = clampWidth(px, SIDEBAR_MIN, SIDEBAR_MAX) },
      setDetails: (d, px: number) => { d.details = clampWidth(px, DETAILS_MIN, DETAILS_MAX) },
--- a/packages/client/ui-layout/src/invariant.ts
+++ b/packages/client/ui-layout/src/invariant.ts
@@ -15,8 +15,8 @@ export const name = 'client-ui-layout-invariant'
 export const inject = ['invariants']

 /**
- * No runtime invariant: shell viewing-state stores (zustand+persist) behind
- * ctx.layout — it emits no cordis events; clamp/prune/concession-chain
+ * No runtime invariant: the shell viewing-state store behind ctx.layout emits
+ * no cordis events; clamp/prune/concession-chain
 * sequencing is asserted directly by this package's columns and service specs.
 */
 const install: InvariantInstaller = () => {}
--- a/packages/client/ui-layout/tests/app-frame.spec.tsx
+++ b/packages/client/ui-layout/tests/app-frame.spec.tsx
@@ -21,8 +21,9 @@ import type {
  SessionId, SessionListState, WorkspaceListState,
 } from '@deepseek-ai/dsh-client-runtime/client'

-// Session-mode switch for the SessionProvider stub prop.
-const sessionMode = { current: true }
+// Session selection controls for the SessionProvider and useSessions stubs.
+const selectedSession = { current: 's-test' as SessionId | undefined }
+const selectedSessionBlank = { current: false }
 const baselinesReady = { current: true }

 // Render-prop contract stub fed through the standard seat prop (the renderer
@@ -31,7 +32,7 @@ const baselinesReady = { current: true }
 // shape. Typed as the seat's own component type so the branded sessionId
 // parameter stays contract-checked.
 const SessionProviderStub: AppFrameProps['SessionProvider'] = ({ children, empty }) =>
-  sessionMode.current ? <>{children('s-test' as Parameters<typeof children>[0])}</> : <>{empty?.() ?? null}</>
+  selectedSession.current === undefined ? <>{empty?.() ?? null}</> : <>{children(selectedSession.current)}</>


 /** Observer stub: captures the callback so tests can fire resizes manually. */
@@ -54,7 +55,6 @@ function hookOf<T>(inst: { subscribe: (fn: () => void) => () => void; getSnapsho
 function mountFrame() {
  window.innerWidth = frameWidth // first-render viewport source before the observer fires
  const instance = createLayoutStore().create()
-  instance.actions.openDetails() // seed: sidebar at default 280, details open at default 360
  const slotCalls: { key: string; props: unknown }[] = []
  const renderSlot = ((key: string, owner: object) => {
    slotCalls.push({ key, props: owner })
@@ -64,32 +64,35 @@ function mountFrame() {
    if (key === 'conversation.empty') return <div data-testid="empty-content" />
    return <div data-testid="other-content" />
  }) as AppFrameProps['renderSlot']
-  const sessionId = 's-test' as SessionId
-  const sessionState = {
-    ids: sessionMode.current ? [sessionId] : [],
-    byId: sessionMode.current
-      ? { [sessionId]: { id: sessionId, displayTitle: 'Test', running: false, blank: false, updatedAt: 1 } }
-      : {},
-    current: sessionMode.current ? sessionId : undefined,
-    phase: 'ready',
-  } as SessionListState
-  const useSessions = ((sel: (s: SessionListState) => unknown) => sel(sessionState)) as never
+  const useSessions = ((sel: (s: SessionListState) => unknown) => {
+    const current = selectedSession.current
+    const sessionState = {
+      ids: current === undefined ? [] : [current],
+      byId: current === undefined
+        ? {}
+        : { [current]: { id: current, displayTitle: 'Test', running: false, blank: selectedSessionBlank.current, updatedAt: 1 } },
+      current,
+      phase: 'ready',
+    } as SessionListState
+    return sel(sessionState)
+  }) as never
  const workspaceState: WorkspaceListState = {
    items: [], state: 'idle', phase: 'ready', error: null,
    baselinesReady: baselinesReady.current, recentWorkspaceId: undefined,
  }
-  const utils = render(
+  const element = () => (
    <AppFrame
-      useStore={hookOf(instance) as never}
+      useStore={hookOf(instance)}
      actions={instance.actions}
      renderSlot={renderSlot}
      useSessions={useSessions}
      useWorkspaces={((sel: (s: WorkspaceListState) => unknown) => sel(workspaceState)) as never}
      SessionProvider={SessionProviderStub}
-    />,
+    />
  )
+  const utils = render(element())
  const frame = utils.container.firstElementChild as HTMLElement
-  return { instance, frame, slotCalls, ...utils }
+  return { instance, frame, slotCalls, rerenderFrame: () => { utils.rerender(element()) }, ...utils }
 }

 function tracks(frame: HTMLElement): number[] {
@@ -109,9 +112,9 @@ function drag(handle: Element, fromX: number, toX: number): void {

 beforeEach(() => {
  frameWidth = 1920
-  sessionMode.current = true
+  selectedSession.current = 's-test' as SessionId
+  selectedSessionBlank.current = false
  baselinesReady.current = true
-  localStorage.clear() // the layout store persists; instances must not bleed across tests
  vi.useFakeTimers()
  vi.stubGlobal('ResizeObserver', ResizeObserverStub)
  vi.stubGlobal('requestAnimationFrame', (cb: FrameRequestCallback) => setTimeout(() => { cb(0) }, 16) as unknown as number)
@@ -154,7 +157,7 @@ describe('AppFrame', () => {
  it('keeps the conversation slot mounted while no session is current', () => {
    // No current session: the session-maybe conversation shell owns the New
    // Session view itself — the center column renders it unconditionally.
-    sessionMode.current = false
+    selectedSession.current = undefined
    const { slotCalls, getByTestId } = mountFrame()
    expect(getByTestId('center-content')).toBeTruthy()
    expect(slotCalls.map(c => c.key)).toContain('conversation')
@@ -169,6 +172,45 @@ describe('AppFrame', () => {
    expect(slotCalls.map(c => c.key)).toContain('details')
  })

+  it('ignores unselected states and closes only when the Session id changes', () => {
+    const { frame, instance, rerenderFrame } = mountFrame()
+    expect(tracks(frame)).toEqual([280, 360])
+
+    selectedSession.current = 's-next' as SessionId
+    act(() => { rerenderFrame() })
+    expect(tracks(frame)).toEqual([280, 0])
+
+    act(() => { instance.actions.openDetails() })
+    selectedSession.current = 's-blank' as SessionId
+    selectedSessionBlank.current = true
+    act(() => { rerenderFrame() })
+    expect(tracks(frame)).toEqual([280, 0])
+    expect(instance.getSnapshot().details).toBe(360)
+
+    selectedSession.current = 's-next' as SessionId
+    selectedSessionBlank.current = false
+    act(() => { rerenderFrame() })
+    expect(tracks(frame)).toEqual([280, 360])
+
+    selectedSession.current = undefined
+    act(() => { rerenderFrame() })
+    expect(tracks(frame)).toEqual([280, 0])
+    selectedSession.current = 's-test' as SessionId
+    act(() => { rerenderFrame() })
+    expect(tracks(frame)).toEqual([280, 0])
+  })
+
+  it('keeps the default details width when the first Session materializes', () => {
+    selectedSession.current = undefined
+    const { frame, instance, rerenderFrame } = mountFrame()
+    expect(tracks(frame)).toEqual([280, 0])
+    expect(instance.getSnapshot().details).toBe(360)
+
+    selectedSession.current = 's-first' as SessionId
+    act(() => { rerenderFrame() })
+    expect(tracks(frame)).toEqual([280, 360])
+  })
+
  it('sidebar slot receives live concession output as owner props', () => {
    const { slotCalls } = mountFrame()
    expect(slotCalls.find(c => c.key === 'sidebar')!.props).toEqual({ collapsed: false, width: 280 })
--- a/packages/client/ui-layout/tests/layout-store.spec.ts
+++ b/packages/client/ui-layout/tests/layout-store.spec.ts
@@ -1,8 +1,8 @@
 // @vitest-environment jsdom
 /**
 * createLayoutStore unit account: init shape, the action write set (clamp
- * inside actions), and the persist key round-trip over jsdom localStorage.
- * Uses the test-sanctioned path: factory self-call + .create() gives the
+ * inside actions), and the absence of browser persistence. Uses the
+ * test-sanctioned path: factory self-call + .create() gives the
 * real engine instance (same create path as production).
 */
 import { beforeEach, describe, expect, it } from 'vitest'
@@ -17,9 +17,9 @@ const PERSIST_KEY = 'dsh.layout.panels'
 beforeEach(() => { localStorage.clear() })

 describe('createLayoutStore', () => {
-  it('initializes with sidebar open at default and details closed', () => {
+  it('initializes both panels at their default widths', () => {
    const { store } = createLayoutStore().create()
-    expect(store.getSnapshot()).toEqual({ sidebar: SIDEBAR_DEFAULT, details: 0 })
+    expect(store.getSnapshot()).toEqual({ sidebar: SIDEBAR_DEFAULT, details: DETAILS_DEFAULT })
  })

  it('each create() is an independent instance (factory is not a singleton)', () => {
@@ -52,6 +52,7 @@ describe('createLayoutStore', () => {

  it('openDetails is a no-op when already open; closeDetails zeroes', () => {
    const { store, actions } = createLayoutStore().create()
+    actions.closeDetails()
    actions.openDetails()
    expect(store.getSnapshot().details).toBe(DETAILS_DEFAULT)
    actions.setDetails(500)
@@ -61,13 +62,16 @@ describe('createLayoutStore', () => {
    expect(store.getSnapshot().details).toBe(0)
  })

-  it('persists under dsh.layout.panels and rehydrates on the next create', () => {
+  it('does not persist panel geometry', () => {
    const first = createLayoutStore().create()
-    first.actions.setSidebar(320)
-    first.actions.openDetails()
-    expect(JSON.parse(localStorage.getItem(PERSIST_KEY) ?? '{}')).toEqual({ sidebar: 320, details: DETAILS_DEFAULT })
+    first.actions.setSidebar(400)
+    first.actions.closeDetails()
+    expect(localStorage.getItem(PERSIST_KEY)).toBeNull()

    const second = createLayoutStore().create()
-    expect(second.store.getSnapshot()).toEqual({ sidebar: 320, details: DETAILS_DEFAULT })
+    expect(second.store.getSnapshot()).toEqual({
+      sidebar: SIDEBAR_DEFAULT,
+      details: DETAILS_DEFAULT,
+    })
  })
 })