Merge final master into Web transcript

packages/client/ui-conversation/src/client/apply.ts

@@ -262,6 +262,13 @@ export function apply(ctx: Context): void {
           })
         },
         loadOlder: () => { void scoped.loadOlder() },
+        forkAt: (seq) => {
+          sessions.fork({ sessionId, atSeq: seq, increaseTitle: true })
+            .then((childId) => { sessions.open(childId) })
+            .catch(() => {
+              // Fork or child-rename failure keeps the source view untouched.
+            })
+        },
       }
     },
   }, ChatView)

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

@@ -23,6 +23,10 @@ export interface AssistantMarkdownProps {
   interrupted?: boolean | undefined
   /** Unix epoch ms for the finalized IconActions clock; omitted while streaming. */
   time?: number | undefined
+  /** Event sequence used as the fork boundary; omitted while streaming. */
+  seq?: number | undefined
+  /** Fork the session through the turn containing this finalized message. */
+  onFork?: ((seq: number) => void) | undefined
 }
 
 function firstLine(text: string): string {
@@ -60,7 +64,7 @@ function ThinkRow({ text, running }: { text: string; running: boolean }) {
 }
 
 export const AssistantMarkdown = memo(function AssistantMarkdown({
-  blocks, streaming, interrupted, time,
+  blocks, streaming, interrupted, time, seq, onFork,
 }: AssistantMarkdownProps) {
   const last = blocks.length - 1
   // Tool-call heads render as tool rows in the chat view's grouping pass, so
@@ -91,6 +95,7 @@ export const AssistantMarkdown = memo(function AssistantMarkdown({
           text={copyText(blocks)}
           time={time}
           clock="end"
+          onBranch={onFork === undefined || seq === undefined ? undefined : () => { onFork(seq) }}
           className={css.actions}
         />
       )}

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

@@ -230,7 +230,7 @@ function StreamingTail({ useSession, onGrow }: {
  * The chat view slot entry: pure component over the composed props (tool rows
  * render through the declared keyed hole's renderSlot share).
  */
-export function ChatView({ useSession, useSessions, useStore, renderSlot, sessionId, openFile, loadOlder }: ChatViewSlotProps) {
+export function ChatView({ useSession, useSessions, useStore, renderSlot, sessionId, openFile, loadOlder, forkAt }: ChatViewSlotProps) {
   const nodes = useSession(s => s.nodes)
   // Workspace root off the session list row: path summaries display relative to it.
   const cwd = useSessions(s => s.byId[sessionId]?.cwd)
@@ -377,6 +377,8 @@ export function ChatView({ useSession, useSessions, useStore, renderSlot, sessio
           streaming={false}
           interrupted={node.interrupted}
           time={node.time}
+          seq={node.seq}
+          onFork={forkAt}
         />
       )
     }
@@ -385,7 +387,7 @@ export function ChatView({ useSession, useSessions, useStore, renderSlot, sessio
     }
     /* v8 ignore next -- tool-result never reaches here: deriveChatFlow folds them into groups. */
     if (node.kind === 'tool-result') return null
-    return <MessageItem key={item.key} node={node} />
+    return <MessageItem key={item.key} node={node} onFork={forkAt} />
   }
 
   return (

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

@@ -1,5 +1,6 @@
-// Shared IconActions chrome for user and assistant messages: copy / branch
-// live (branch still a stub), date-aware clock, optional edit stub.
+// Shared IconActions chrome for user and assistant messages: copy live,
+// branch wired through onBranch, date-aware clock,
+// optional edit stub.
 
 import { useCallback } from 'react'
 import {
@@ -18,17 +19,19 @@ export interface MessageIconActionsProps {
   clock: 'start' | 'end'
   /** When true, append the stub edit control (user bubble). */
   edit?: boolean | undefined
+  /** Fork the session at this message. */
+  onBranch?: (() => void) | undefined
   /** Parent layout 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.
+ * @param props - Copy text, event time, clock side, optional edit, branch callback, className.
  * @returns The actions row element.
  */
 export function MessageIconActions({
-  text, time, clock, edit, className,
+  text, time, clock, edit, onBranch, className,
 }: MessageIconActionsProps) {
   const day = useCalendarDay()
   const onCopy = useCallback(() => {
@@ -48,7 +51,7 @@ export function MessageIconActions({
         </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">
+        <button type="button" className={css.action} aria-label="在新对话中分支" onClick={onBranch}>
           <IconBranchOutline16 />
         </button>
       </Tooltip>

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

@@ -17,6 +17,8 @@ import css from './MessageItem.module.css'
 
 export interface MessageItemProps {
   node: UserMessageNode | SteeringMessageNode | ContextMessageNode | CompactionSummaryNode | UnknownSurfaceNode
+  /** Fork the session through the turn containing this message (user-bubble branch action). */
+  onFork?: (seq: number) => void
 }
 
 function contentText(content: readonly unknown[]): { text: string; rest: unknown[] } {
@@ -62,7 +64,7 @@ function projectUserText(text: string): ReactNode {
   return <>{parts}</>
 }
 
-export const MessageItem = memo(function MessageItem({ node }: MessageItemProps) {
+export const MessageItem = memo(function MessageItem({ node, onFork }: MessageItemProps) {
   switch (node.kind) {
     case 'user': {
       const { text, rest } = contentText(node.content)
@@ -77,6 +79,7 @@ export const MessageItem = memo(function MessageItem({ node }: MessageItemProps)
             time={node.time}
             clock="start"
             edit
+            onBranch={onFork === undefined ? undefined : () => { onFork(node.seq) }}
             className={css.actions}
           />
         </div>

packages/client/ui-conversation/src/client/contract/slots.ts

@@ -419,6 +419,8 @@ export interface ChatViewInjected {
    */
   openFile: (path: string) => void
   loadOlder: () => void
+  /** Fork the session through the turn containing the message at `seq`, then open the child. */
+  forkAt: (seq: number) => void
 }
 
 /** Full chat-view component props: runtime share & the declared toolview/commandview holes' render share & store share & injected share. */

packages/client/ui-conversation/src/client/skeleton/ApprovalPanel.module.css

@@ -19,6 +19,13 @@
   border-radius: 20px;
   background: var(--dsw-specific-input-major);
   box-shadow: var(--dsw-shadow-lv2);
+  /* Elevated surface in dark, same as the menus: `.body` inside scrolls once
+     the justification or command passes the cap, so the thumb takes the l2
+     pair. Declared on the card because the elevation belongs to the surface,
+     and the custom properties inherit down to the region that actually
+     scrolls (see ui-theme styles/scrollbar.css for the rebinding contract). */
+  --dsh-scrollbar-thumb: var(--dsw-alias-scrollbar-bg-l2);
+  --dsh-scrollbar-thumb-hover: var(--dsw-alias-scrollbar-hover-l2);
 }
 
 /* Tinted full-width header band. */
@@ -40,11 +47,22 @@
   background: var(--dsw-alias-state-warn-primary);
 }
 
+/* Scroll region: an agent's justification and its command are unbounded model
+   text (a one-line `cd` or a 40-line heredoc), and the seat sits in a
+   fixed-height column — uncapped, a long command pushed the action row past
+   the viewport and the approval could not be answered at all. The strip and
+   the action row stay outside, so the buttons are always on screen. */
 .body {
   display: flex;
   flex-direction: column;
   gap: 6px;
-  padding: 12px 16px 14px;
+  /* border-box so the cap is the region's OUTER height: the composer's draft
+     area counts its padding inside the same number, and the two seats are
+     only interchangeable if they occupy the same box. */
+  box-sizing: border-box;
+  max-height: var(--dsh-composer-text-max-height);
+  overflow-y: auto;
+  padding: 12px 16px 0;
 }
 
 /* The model's justification is the panel's message, not a footnote. */
@@ -63,11 +81,15 @@
   word-break: break-all;
 }
 
+/* Card-level row, not body content. Its padding reproduces the metrics the row
+   had inside the body: 14px above (the flex gap of 6 plus the row's 8px top
+   margin, neither of which reaches it out here) and the body's former 14px
+   bottom pad below, so the resting card is unchanged. */
 .actionRow {
   display: flex;
   justify-content: flex-end;
   gap: 8px;
-  margin-top: 8px;
+  padding: 14px 16px 14px;
 }
 
 .allow,

packages/client/ui-conversation/src/client/skeleton/ApprovalPanel.tsx

@@ -4,7 +4,11 @@
 // pending, this panel occupies the composer slot in place of the InputBar:
 // an amber "Waiting for approval" strip on the card top, the model's
 // justification as the headline, the paired command in muted code text, and
-// a right-aligned refuse/allow action row. One-shot: the buttons disable
+// a right-aligned refuse/allow action row. Justification and command are
+// unbounded model text, so they scroll inside the card at the shared composer
+// cap (`data-approval-scroll`) and the action row stays outside it — the
+// buttons must be reachable no matter how long the command is.
+// One-shot: the buttons disable
 // after a click and the panel leaves (the InputBar returns) on the broadcast
 // resolved frame. The draft's "Always allow this type" is deferred with
 // grant storage.
@@ -53,17 +57,20 @@ function ApprovalFlow({ pending, command }: { pending: PendingApproval; command?
     <div className={css.root} data-approval-key={pending.key}>
       <div className={css.card}>
         <div className={css.strip}><span className={css.dot} />等待审批</div>
-        <div className={css.body}>
+        {/* Tab stop: the region scrolls once the command passes the cap and
+            holds nothing focusable of its own, so without one a keyboard-only
+            user cannot reach the command's tail before answering. */}
+        <div className={css.body} data-approval-scroll="" tabIndex={0} role="group" aria-label="审批详情">
           <div className={css.headline}>{pending.reason ?? `工具 ${pending.toolName} 请求越权执行`}</div>
           {command !== undefined && <div className={css.command}>{command}</div>}
-          <div className={css.actionRow}>
-            <button type="button" className={css.reject} disabled={answered} onClick={() => { answer('rejected') }}>
-              拒绝
-            </button>
-            <button type="button" className={css.allow} disabled={answered} onClick={() => { answer('allowed-once') }}>
-              允许一次
-            </button>
-          </div>
+        </div>
+        <div className={css.actionRow}>
+          <button type="button" className={css.reject} disabled={answered} onClick={() => { answer('rejected') }}>
+            拒绝
+          </button>
+          <button type="button" className={css.allow} disabled={answered} onClick={() => { answer('allowed-once') }}>
+            允许一次
+          </button>
         </div>
       </div>
     </div>

packages/client/ui-conversation/src/client/skeleton/ConversationRoot.module.css

@@ -143,6 +143,14 @@
   display: flex;
   flex: none;
   flex-direction: column;
+  /* One cap for every scrolling text region a composer seat can hold: the
+     InputBar draft (figma Input 75:8208 max 14 lines × 24px line) and the
+     takeover panels' bodies top out at the same height, so electing a
+     takeover never grows the footer past the card it replaces. Declared on
+     the seat because it is the chain's only shared ancestor — fallback and
+     elected overlay are siblings — and custom properties inherit down to
+     whichever entry is mounted. */
+  --dsh-composer-text-max-height: 336px;
 }
 
 /* Active phase: header is ordinary column chrome above the scrollport (not

packages/client/ui-conversation/src/client/skeleton/InputBar.module.css

@@ -209,7 +209,9 @@
 .mirror {
   visibility: hidden;
   pointer-events: none;
-  max-height: 336px;
+  /* 14-line cap, shared with the composer takeovers (declared on
+     ConversationRoot .composerSeat). */
+  max-height: var(--dsh-composer-text-max-height);
   overflow: hidden;
 }