fix(web): grant turn-tail IconActions only after the turn ends

`assistantActionsSeqs` picked the last content-text assistant of each turn
from the finalized transcript alone. That quantity is stable only once the
turn closes: while a turn is still producing steps, the narration written
before a tool call is the last content assistant so far, so copy, branch,
and the clock appeared under an intermediate sentence for as long as the
tool ran and then moved down to the next step's text.

Pass `ConversationSnapshot.turnEnds` into the derivation and grant the row
only inside a turn that has a durable `turn/end`. This is the same
completion fact the branch control and the `Ran for` label already read, so
the three parts of one row now agree; mid-turn narration owns nothing, and
the seat appears once under the settled answer.

`hasContentText` moves to chat-flow.ts so the ownership gate and
AssistantMarkdown's mount gate cannot drift apart.

apps/web/tests/turn-tail-actions.e2e.ts pins both states through the
assembled application: a hang sidecar on the second model call parks a turn
whose first step narrated before calling bash, and the two goldens hold the
parked flow and the flow after stopping.

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: 7bd0d551fc41967326dd9860f5c31a99ea3c254a
-README.zh.md: d339f6423d9a9f77c02d86ad0b8e57bd0baba52b
+README.md: c01be00a82a23feeaae18bd55668163803de9ef7
+README.zh.md: c5102576e4e030f0662135baa6c9a3d30e1ad846

packages/client/ui-conversation/README.md

@@ -63,7 +63,7 @@ None; this package neither assembles nor sends a provider request.
 - **Compaction markers show no scale** — the row does not yet report how many messages or which range the checkpoint replaced.
 - **Stats-line durations and speeds cover the in-window flow only** — LLM and tool wall times plus the TTFT and throughput averages fold the snapshot's assistant `timing` and tool call/result pairs, so nodes outside the loaded event window (older history) are not counted.
 - **The details panel has no entry point** — `ChatViewInjected.openDetails` is implemented but uncalled, so the raw selected-call display is unreachable in the assembled application. There is no Input/Output/Metadata switch, Prev/Next stepping, or trajectory deep link.
-- **Assistant per-message paging is a reserved slot** — drawn in the design, not implemented. The finalized content IconActions row (copy / clock / branch) ships under the last content-text assistant of each turn only; mid-turn narration and Think-only nodes stay chrome-free. Branch stays disabled unless that message is also the last transcript node of a completed turn; when enabled, it forks through that turn, increments the inherited title on the client, and opens the child. A fork or rename failure leaves the source selected ([decision](../../../.agents/notes/implemented/bug-fix/2026-08-02-message-fork-actions-require-completed-turn-tail.md)).
+- **Assistant per-message paging is a reserved slot** — drawn in the design, not implemented. The finalized content IconActions row (copy / clock / branch) ships under the last content-text assistant of each turn that has ended; mid-turn narration, Think-only nodes, and every node of a turn still producing steps stay chrome-free. Branch stays disabled unless that message is also the last transcript node of a completed turn; when enabled, it forks through that turn, increments the inherited title on the client, and opens the child. A fork or rename failure leaves the source selected ([decision](../../../.agents/notes/implemented/bug-fix/2026-08-02-message-fork-actions-require-completed-turn-tail.md)).
 - **Sent user messages cannot be edited** — user bubbles retain clock, copy, and branch; branch stays disabled unless a completed turn's transcript ends at that user message. Editing returns with the capability behind it: a client mutation over a settled user message, plus the host behavior for the turn that already consumed it ([decision](../../../.agents/notes/implemented/simplification/2026-07-31-drop-user-message-edit-stub.md)).
 - **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 has no durable grant control** — it supports allow-once and reject only.

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

@@ -63,7 +63,7 @@ Host 带 placement 的 `session/queue` 快照也会携带待处理 steering。Qu
 - **压缩标记不显示规模**：该行尚不报告检查点替换了多少条消息或哪段范围。
 - **统计行的耗时与速率只覆盖窗口内消息流**：LLM 与工具墙钟时间以及 TTFT 与吞吐平均值由快照的 assistant `timing` 与工具 call/result 配对折算，落在已加载事件窗口之外的节点（更早的历史）不计入。
 - **详情面板没有入口**：`ChatViewInjected.openDetails` 虽已实现却无人调用，因此以原始形式显示已选择调用的那部分在组装后的应用中不可达。没有 Input/Output/Metadata 切换、Prev/Next 步进，也没有 trajectory 深链接。
-- **assistant 逐消息分页是预留 slot**：设计中已有图稿，尚未实现。已定稿的内容 IconActions 行（复制／时钟／分支）只挂在每个轮次中最后一条带 text 内容的 assistant 下；轮次中间的叙述与纯 Think 节点不带 chrome。除非该消息同时也是已完成轮次的最后一个 transcript 节点，否则分支保持禁用；启用后，它会 fork 到该轮次末尾，在 client 端递增继承标题并打开子会话。fork 或改名失败时源会话保持选中（[决策](../../../.agents/notes/implemented/bug-fix/2026-08-02-message-fork-actions-require-completed-turn-tail.md)）。
+- **assistant 逐消息分页是预留 slot**：设计中已有图稿，尚未实现。已定稿的内容 IconActions 行（复制／时钟／分支）只挂在每个已结束轮次中最后一条带 text 内容的 assistant 下；轮次中间的叙述、纯 Think 节点，以及仍在产出步骤的轮次里的所有节点都不带 chrome。除非该消息同时也是已完成轮次的最后一个 transcript 节点，否则分支保持禁用；启用后，它会 fork 到该轮次末尾，在 client 端递增继承标题并打开子会话。fork 或改名失败时源会话保持选中（[决策](../../../.agents/notes/implemented/bug-fix/2026-08-02-message-fork-actions-require-completed-turn-tail.md)）。
 - **已发送的 user 消息无法编辑**：user 气泡保留时钟、复制和分支；除非已完成轮次的 transcript 结束于该 user 消息，否则分支保持禁用。编辑功能要与其背后的能力一起回归：既需要针对已定稿 user 消息的 client 变更，也需要 host 侧对已经消费过它的轮次给出行为（[决策](../../../.agents/notes/implemented/simplification/2026-07-31-drop-user-message-edit-stub.md)）。
 - **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。

packages/client/ui-conversation/src/client/chat/AssistantMarkdown.tsx

@@ -4,10 +4,10 @@
 // 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 content (text) nodes append IconActions once streaming ends
-// (`time` is omitted for mid-turn narration); their branch action is enabled
-// only when the node is also the completed turn's transcript tail. Think /
-// tool-head-only nodes stay chrome-free.
+// Finalized content (text) nodes append IconActions once their turn ends
+// (`time` is omitted for mid-turn narration and while the turn still runs);
+// their branch action is enabled only when the node is also the completed
+// turn's transcript tail. Think / tool-head-only nodes stay chrome-free.
 
 import { memo, useMemo } from 'react'
 import type { AssistantBlock } from '@deepseek-ai/dsh-client-runtime/client'
@@ -15,6 +15,7 @@ import {
   IconThinkOutline14, JsonBlock, MarkdownText,
 } from '@deepseek-ai/dsh-client-ui-primitives'
 import type { ChatViewSlotProps } from '../contract/slots.ts'
+import { hasContentText } from './chat-flow.ts'
 import { MessageIconActions } from './MessageIconActions.tsx'
 import { ToolRow } from './ToolRow.tsx'
 import css from './AssistantMarkdown.module.css'
@@ -25,7 +26,8 @@ export interface AssistantMarkdownProps {
   /** Frozen partial of an aborted turn: rendered with a stopped marker. */
   interrupted?: boolean | undefined
   /** Unix epoch ms for the IconActions clock; omitted while streaming or when
-   *  the parent withholds chrome (mid-turn content assistants). */
+   *  the parent withholds chrome (mid-turn content assistants and every node
+   *  of a turn that has not ended). */
   time?: number | undefined
   /** Turn wall time in ms for the IconActions run-time label; omitted when the
    *  turn's triggering input is outside the loaded window. */
@@ -65,11 +67,6 @@ function copyText(blocks: readonly AssistantBlock[]): string {
   return parts.join('')
 }
 
-/** True when the node has model-visible text content worth chrome under. */
-function hasContentText(blocks: readonly AssistantBlock[]): boolean {
-  return blocks.some(block => block.kind === 'text' && block.text.trim() !== '')
-}
-
 /** Reasoning block as the Think variant summary row (figma 39:28304). */
 function ThinkRow({ text, running, t }: { text: string; running: boolean; t: AssistantMarkdownProps['t'] }) {
   return (

packages/client/ui-conversation/src/client/chat/ChatView.tsx

@@ -358,9 +358,10 @@ export function ChatView({
     [inbox],
   )
   const activeRetry = useMemo(() => activeRetrySeq(nodes, running), [nodes, running])
-  // Only the last content assistant of each turn owns IconActions; mid-turn
-  // text (before tools) omits `time` so AssistantMarkdown stays chrome-free.
-  const actionSeqs = useMemo(() => assistantActionsSeqs(nodes), [nodes])
+  // Only the last content assistant of each completed turn owns IconActions;
+  // mid-turn text and every node of a running turn omit `time`, so
+  // AssistantMarkdown stays chrome-free until the answer settles.
+  const actionSeqs = useMemo(() => assistantActionsSeqs(nodes, turnEnds), [nodes, turnEnds])
   const branchSeqs = useMemo(() => messageBranchSeqs(nodes, turnEnds), [nodes, turnEnds])
   const runningTurnStart = useMemo(() => runningTurnStartTime(turnTimings), [turnTimings])
   const turnMetrics = useMemo(() => deriveTurnMetrics(nodes), [nodes])

packages/client/ui-conversation/src/client/chat/chat-flow.ts

@@ -17,8 +17,14 @@ export type ChatFlowItem =
   | { kind: 'node'; key: string; node: ConversationNode }
   | { kind: 'tool-group'; key: string; results: readonly ToolResultNode[] }
 
-/** True when the node has model-visible text content worth IconActions chrome. */
-function hasContentText(blocks: readonly AssistantBlock[]): boolean {
+/**
+ * True when the node has model-visible text content worth IconActions chrome.
+ * Shared with {@link AssistantMarkdown}'s mount gate so ownership and mounting
+ * cannot diverge.
+ * @param blocks - assistant blocks of one finalized node.
+ * @returns Whether any text block carries non-blank content.
+ */
+export function hasContentText(blocks: readonly AssistantBlock[]): boolean {
   return blocks.some(block => block.kind === 'text' && block.text.trim() !== '')
 }
 
@@ -34,14 +40,20 @@ function rendersNothing(node: ConversationNode): boolean {
 
 /**
  * Seq set of assistants that own IconActions: the last content-text assistant
- * in each turn. Mid-turn narration (text before tools) stays chrome-free.
+ * of each *completed* turn. A turn without a `turn/end` in the window is still
+ * producing steps, so its latest narration is not the settled answer and owns
+ * nothing; mid-turn narration of a completed turn stays chrome-free too.
  * @param nodes - snapshot nodes (surface order).
+ * @param turnEnds - completed turn boundaries retained from the event window.
  * @returns Seq values ChatView may pass as `time` into AssistantMarkdown.
  */
-export function assistantActionsSeqs(nodes: readonly ConversationNode[]): ReadonlySet<number> {
+export function assistantActionsSeqs(
+  nodes: readonly ConversationNode[],
+  turnEnds: ReadonlyMap<number, number>,
+): ReadonlySet<number> {
   const lastByTurn = new Map<number, number>()
   for (const node of nodes) {
-    if (node.kind !== 'assistant' || !hasContentText(node.blocks)) continue
+    if (node.kind !== 'assistant' || !turnEnds.has(node.turn) || !hasContentText(node.blocks)) continue
     lastByTurn.set(node.turn, node.seq)
   }
   return new Set(lastByTurn.values())

packages/client/ui-conversation/tests/chat-view.spec.tsx

@@ -225,12 +225,12 @@ describe('chat-flow derivation', () => {
     expect(flowKeys(deriveChatFlow([toolResult(3, 'a'), assistant(4, 'found'), toolResult(5, 'b')]))).toBe('g3|n4|g5')
   })
 
-  it('assistantActionsSeqs keeps only the last content assistant per turn', () => {
+  it('assistantActionsSeqs keeps only the last content assistant per completed turn', () => {
     const thinkOnly: AssistantMessageNode = {
       kind: 'assistant', seq: 3, time: 3_000, turn: 1, step: 2,
       blocks: [{ kind: 'reasoning', text: 'planning' }],
     }
-    const seqs = assistantActionsSeqs([
+    const nodes: ConversationNode[] = [
       user(1, 'hi'),
       assistant(2, 'looking', 1),
       thinkOnly,
@@ -238,8 +238,11 @@ describe('chat-flow derivation', () => {
       assistant(5, 'done', 1),
       user(6, 'again'),
       assistant(7, 'second turn', 2),
-    ])
-    expect([...seqs].sort((a, b) => a - b)).toEqual([5, 7])
+    ]
+    expect([...assistantActionsSeqs(nodes, new Map([[1, 5], [2, 7]]))].sort((a, b) => a - b)).toEqual([5, 7])
+    // Turn 2 is still producing steps: its latest narration owns nothing, and
+    // the settled turn 1 keeps its seat.
+    expect([...assistantActionsSeqs(nodes, new Map([[1, 5]]))]).toEqual([5])
   })
 
   it('runningTurnStartTime selects the latest turn/start without a turn/end', () => {
@@ -401,7 +404,9 @@ describe('ChatView', () => {
     expect(view.getAllByText('interrupt now')).toHaveLength(1)
     expect(view.container.querySelector('[data-pending-steering]')).toBeNull()
     expect(view.getAllByText('插话')).toHaveLength(1)
-    expect(view.getAllByRole('button', { name: '复制' })).toHaveLength(2)
+    // Only the durable steering bubble: the turn is still running, so its
+    // assistant narration owns no footer yet.
+    expect(view.getAllByRole('button', { name: '复制' })).toHaveLength(1)
     const durableBubble = view.getByText('interrupt now').closest('[class*="userRow"]') as HTMLElement
     const unavailable = within(durableBubble).getByRole('button', { name: '在新对话中分支' })
     expect(unavailable.getAttribute('aria-disabled')).toBe('true')
@@ -525,6 +530,28 @@ describe('ChatView', () => {
     expect(branchButtons.map(button => button.getAttribute('aria-disabled'))).toEqual(['true', null, 'true', null])
   })
 
+  it('withholds assistant IconActions while the turn is still running', () => {
+    const h = makeHarness({
+      running: true,
+      runningCalls: [runningCall('a')],
+      nodes: [
+        user(1, 'first'),
+        assistant(2, 'previous answer', 1),
+        user(3, 'second'),
+        assistant(4, 'mid-turn text', 2),
+      ],
+      turnEnds: new Map([[1, 2]]),
+    })
+    const view = render(<h.ChatView {...h.props} />)
+    // 2 user + the settled turn-1 tail; turn 2's narration stays chrome-free
+    // while its tool runs, so the footer never appears and then moves.
+    expect(view.getAllByRole('button', { name: '复制' })).toHaveLength(3)
+    expect(view.getByText('mid-turn text')).toBeTruthy()
+    // turn/end lands: the same node becomes the settled answer and takes the seat.
+    act(() => { h.set({ running: false, runningCalls: [], turnEnds: new Map([[1, 2], [2, 5]]) }) })
+    expect(view.getAllByRole('button', { name: '复制' })).toHaveLength(4)
+  })
+
   it('the actions-owning assistant footer shows the turn run time', () => {
     const h = makeHarness({
       nodes: [