feat(web): name context sources and mark steering in the transcript

Every logged non-user user/message collapsed into one identical
「上下文注入」 row, and mid-turn steering rendered in exactly the bubble a
turn-opening prompt uses, so the transcript could not say what had been
added or which message interrupted a running turn.

TranscriptAdapter and the history fold now attach a provenance view to
each context node, computed by contextProvenance() from the durable
source alone: a role (inject, or recall for a cross-session snapshot)
and a producer name read out of the log — instruction paths for
workspace-instructions, session titles for session-reference, the plugin
id for a plugin source, and the bare kind for any other. No client-side
table of producer names, so a renamed or newly mounted producer stays
identifiable without a client release and a foreign log projects like a
live one. ContextInjectionRow titles itself from the role and shows the
name beside it; MessageItem captions durable and pending steering
bubbles.

The caption reverses one clause of the no-interjection-chrome decision,
which removed it because the composer could not steer; composer steering
shipped afterwards without amending that note, so this change supplies
the product decision its reintroduction clause required and corrects the
stale facts left in it.

Fixes #1291

packages/client/ui-conversation/src/client/chat/ContextInjectionRow.module.css

@@ -12,6 +12,20 @@
   color: var(--dsw-alias-label-secondary);
 }
 
+/* Producer name beside the role title: ToolRow's summary geometry, so the two
+   disclosure rows keep one 24px rhythm; subordinate color, truncated when long. */
+.source {
+  flex: 1 1 auto;
+  min-width: 0;
+  overflow: hidden;
+  margin-left: 4px;
+  color: var(--dsw-alias-label-tertiary);
+  font-size: 14px;
+  line-height: 24px;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
 .body {
   box-sizing: border-box;
   width: calc(100% - 22px);

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

@@ -48,16 +48,22 @@ function inlineJson(payload: unknown): string {
 export interface ContextInjectionRowProps {
   content: ContextMessageNode['content']
   source: ContextMessageNode['source']
+  /** Role and producer name projected from the durable source. */
+  provenance: ContextMessageNode['provenance']
   /** The owning view's locale seat, passed down as a plain prop. */
   t: ChatViewSlotProps['t']
 }
 
 /**
  * Render logged context with the Tool calls disclosure chrome from Figma.
- * @param props - Durable content and source provenance.
+ *
+ * The header names the role the context plays and, beside it, the producer the
+ * durable source identifies, so a reader can tell an injected skill catalog
+ * from a workspace instruction file or a recalled session without expanding.
+ * @param props - Durable content, its projected provenance, and the locale seat.
  * @returns A collapsed context row with a bounded JSON body.
  */
-export function ContextInjectionRow({ content, source, t }: ContextInjectionRowProps) {
+export function ContextInjectionRow({ content, source, provenance, t }: ContextInjectionRowProps) {
   const [open, setOpen] = useState(false)
   const body = useMemo(() => {
     if (!open) return ''
@@ -72,7 +78,11 @@ export function ContextInjectionRow({ content, source, t }: ContextInjectionRowP
       className={css.root}
       icon={<IconBrowseOutline16 size={14} />}
       chevronClassName={css.chevron}
-      title={t('message.contextInjection')}
+      title={t(provenance.role === 'recall' ? 'message.contextRecall' : 'message.contextInjection')}
+      collapsedContent={provenance.label === null ? undefined : (
+        <span className={css.source} data-context-source>{`· ${provenance.label}`}</span>
+      )}
+      keepContentWhenOpen
       open={open}
       expandable
       expandOnRowClick

packages/client/ui-conversation/src/client/chat/MessageItem.module.css

@@ -8,6 +8,15 @@
   gap: 6px;
 }
 
+/* Steering caption above the bubble: mid-turn interjections carry the same
+   bubble as a turn-opening prompt, so the transcript names which one this is. */
+.steeringMark {
+  padding-right: 4px;
+  color: var(--dsw-alias-label-tertiary);
+  font-size: 12px;
+  line-height: 16px;
+}
+
 .bubble {
   /* 525px cap inside the 736 column; percentage keeps narrow windows sane. */
   max-width: min(525px, 82%);

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

@@ -171,19 +171,22 @@ function projectUserText(text: string): ReactNode {
 
 /** Right-aligned bubble shared by user and steering rows. */
 function UserStyleBubble({
-  content, actions, pending = false, t,
+  content, actions, pending = false, steering = false, t,
 }: {
   content: readonly unknown[]
   /** Optional IconActions (or similar) below the bubble; receives the joined text. */
   actions?: (text: string) => ReactNode
   /** Whether this is the Host-authoritative pre-admission steering projection. */
   pending?: boolean
+  /** Marks the bubble as mid-turn steering rather than a turn-opening prompt. */
+  steering?: boolean
   t: ChatViewSlotProps['t']
 }): ReactNode {
   const { text, rest } = contentText(content)
   const truncated = (total: number): string => t('json.truncated', { total })
   return (
     <div className={css.userRow} data-pending-steering={pending || undefined} data-time-hover-root>
+      {steering && <span className={css.steeringMark} data-steering-mark>{t('message.steering')}</span>}
       <div className={css.bubble}>
         {projectUserText(text)}
         {rest.map((block, i) => <JsonBlock key={i} label={t('message.extraBlock')} payload={block} truncatedLabel={truncated} />)}
@@ -207,6 +210,7 @@ export function PendingSteeringBubble({ content, t }: {
     <UserStyleBubble
       content={content}
       pending
+      steering
       t={t}
       actions={text => (
         <MessageIconActions
@@ -231,6 +235,7 @@ export const MessageItem = memo(function MessageItem({
       return (
         <UserStyleBubble
           content={node.content}
+          steering={node.kind === 'steering'}
           t={t}
           actions={text => (
             <MessageIconActions
@@ -247,7 +252,12 @@ export const MessageItem = memo(function MessageItem({
       )
     case 'context':
       return (
-        <ContextInjectionRow content={node.content} source={node.source} t={t} />
+        <ContextInjectionRow
+          content={node.content}
+          source={node.source}
+          provenance={node.provenance}
+          t={t}
+        />
       )
     case 'compaction':
       return <CompactionItem node={node} t={t} />

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

@@ -52,6 +52,8 @@ export const zh = {
   'chat.toBottom': '回到底部',
   'message.extraBlock': '附加内容块',
   'message.contextInjection': '上下文注入',
+  'message.contextRecall': '跨会话召回',
+  'message.steering': '插话',
   'message.compaction': '上下文已压缩',
   'message.compaction.expand': '点击查看压缩摘要',
   'message.compaction.unavailable': '压缩摘要不可用',
@@ -163,6 +165,8 @@ export const en = {
   'chat.toBottom': 'Back to bottom',
   'message.extraBlock': 'Extra content block',
   'message.contextInjection': 'Context injection',
+  'message.contextRecall': 'Session recall',
+  'message.steering': 'Steer',
   'message.compaction': 'Context compacted',
   'message.compaction.expand': 'View compaction summary',
   'message.compaction.unavailable': 'Compaction summary unavailable',