fix(web): apply review round — notice anchors before turn-tail, published node kind, fixture nextTurn

Anchor the max-tokens notice between the closing assistant and the
turn-tail so the tail stays the turn's last chat node and its branch
action survives; forward the ChatNodeDataMap augmentation through the
client entry so built declarations publish the new kind; advance the
fixture's nextTurn past the appended history; drop the engine-unreachable
buildViewNode fallback; deduplicate the runtime README tail sentence.

packages/client/ui-conversation/src/client/conversation-nodes/common.ts

@@ -7,11 +7,14 @@ import type {
 
 /**
  * Relative positions in one durable event's seq neighborhood: interrupted
- * Assistant, its follow-up Nodes, then follow-ups to an ordinary final.
+ * Assistant, its follow-up Nodes, then follow-ups to an ordinary final. The
+ * max-tokens notice sits between a closing Assistant and the turn-tail so the
+ * tail stays the turn's last node and keeps its branch action enabled.
  */
 export const CHAT_SYNTHETIC_SEQ_OFFSETS = {
   interruptedAssistant: -0.9,
   interruptedFollowup: -0.8,
+  maxTokensNotice: 0.05,
   finalizedFollowup: 0.1,
 } as const
 

packages/client/ui-conversation/src/client/conversation-nodes/turn-max-tokens.ts

@@ -2,7 +2,7 @@ import type { Context } from '@deepseek-ai/cordis'
 import type {
   ConversationMatch, ConversationNodeContext, ConversationNodeDefinition, TurnMaxTokensNode,
 } from '@deepseek-ai/dsh-client-runtime/client'
-import { chatNode } from './common.ts'
+import { CHAT_SYNTHETIC_SEQ_OFFSETS, chatNode } from './common.ts'
 
 declare module '@deepseek-ai/dsh-client-ui-conversation/client' {
   interface ChatNodeDataMap {
@@ -23,6 +23,21 @@ function lastStep(context: ConversationNodeContext<TurnMaxTokensState>): number
   return location.turn.steps.at(-1)?.step ?? 0
 }
 
+/**
+ * Anchor the notice between the closing Assistant and the turn-tail so the
+ * tail stays the turn's last Chat node and keeps its branch action enabled.
+ * Without a closing text Assistant there is no branch action to protect, and
+ * the turn/end seq keeps the notice at the truncation point.
+ */
+function noticeAnchor(context: ConversationNodeContext<TurnMaxTokensState>, seq: number): number {
+  const location = context.start?.location ?? context.matches[0]?.location
+  if (location?.kind !== 'turn' && location?.kind !== 'step') return seq
+  const closing = location.turn.data.get('turn-tail')?.closing
+  return closing === null || closing === undefined
+    ? seq
+    : closing.finalNode.seq + CHAT_SYNTHETIC_SEQ_OFFSETS.maxTokensNotice
+}
+
 function stateFrom(match: ConversationMatch): TurnMaxTokensState | undefined {
   if (match.event.type !== 'turn/end' || match.event.data.reason.kind !== 'max-tokens') return undefined
   return { turn: match.event.data.turn, seq: match.event.seq, time: match.event.time }
@@ -46,7 +61,6 @@ export const turnMaxTokensDefinition: ConversationNodeDefinition<TurnMaxTokensSt
   update: context => context.state,
   buildViewNode: (context) => {
     const state = context.state
-      ?? context.matches.map(stateFrom).find(candidate => candidate !== undefined)
     if (state === undefined) return null
     const node: TurnMaxTokensNode = {
       kind: 'turn-max-tokens',
@@ -55,7 +69,7 @@ export const turnMaxTokensDefinition: ConversationNodeDefinition<TurnMaxTokensSt
       turn: state.turn,
       step: lastStep(context),
     }
-    return chatNode(context, 'turn-max-tokens', node.seq, node)
+    return chatNode(context, 'turn-max-tokens', noticeAnchor(context, state.seq), node)
   },
 }
 

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

@@ -11,6 +11,7 @@ export type {} from './conversation-nodes/message.ts'
 export type {} from './conversation-nodes/retry.ts'
 export type {} from './conversation-nodes/tool.ts'
 export type {} from './conversation-nodes/turn-error.ts'
+export type {} from './conversation-nodes/turn-max-tokens.ts'
 export type {} from './conversation-nodes/turn-tail.ts'
 
 export { apply, inject } from './apply.ts'