Interleave live parts per turn and mark commentary process on tool.call

Why: liveToMessage emitted all text buckets then all tools, while the
persisted message interleaves per turn (thinking, text, calls), so parts
reordered on reconcile with 2+ tool turns. Commentary stayed in the reply
area until the next turn's text bucket appeared, because the process flag
was positional (i < length - 1) instead of tool-driven.

Evidence: LiveState now holds an arrival-ordered items stream
(thinking/text deltas merge into their last segment; tools land in place),
so event order - which matches the backend's per-turn append order - maps
1:1 onto persisted parts. A text segment is process iff a tool.call lands
before the next thinking/text segment, aligning with the backend's
Process: len(calls) > 0; the collapse predicate moved to testable
showProcessInline. Long replies (>800 chars) now show a 100-char excerpt
and label the count as Markdown source length. vitest 27/27 pass (was 5
live cases, now 12 incl. multi-turn order, immediate process marking,
collapse predicate); tsc -b clean.

Impact: streaming UI no longer reshuffles parts across turns or on final
reconcile; tool-turn commentary folds into the process area as soon as the
tool call arrives. Residual edge (documented in live.ts): a silent
tool-only turn with no text and no thinking attributes its call to the
previous text segment.

Refs: code review of feature/chat-process-split-r1 (2026-09-30)

src/components/Conversation.tsx

@@ -4,7 +4,7 @@ import { useEffect, useMemo, useRef, useState } from 'react'
 import { marked } from 'marked'
 import { api } from '../api'
 import { store, useStore, activeRun, type LiveState, type ContextObs } from '../store'
-import { liveToMessage } from '../live'
+import { liveToMessage, showProcessInline } from '../live'
 import type { Message, Part, HITLCard } from '../contracts'
 import { UIRenderer, InlineConfirmCard, hasOpenConfirm } from '@ui'
 import { docBridge } from './Workbench'
@@ -87,11 +87,14 @@ function ProcessCollapse({ parts }: { parts: Part[] }) {
 const LONG_REPLY_CHARS = 800
 
 function LongReplyCollapse({ text }: { text: string }) {
+  // 摘句取压缩空白后的前 100 字；字数按 Markdown 源码长度计。
+  const excerpt = text.replace(/\s+/g, ' ').trim().slice(0, 100)
   return (
     <details className="process-collapse long-reply">
       <summary>
         <span>📄 长回复</span>
-        <span>{text.length} 字（点击展开）</span>
+        <span>{text.length} 字（按 Markdown 源码计）</span>
+        {excerpt && <span style={{ color: 'var(--text-faint)' }}>{excerpt}…</span>}
       </summary>
       <div className="body">
         <div className="part-text" dangerouslySetInnerHTML={{ __html: marked.parse(text) }} />
@@ -113,7 +116,7 @@ function AssistantMessage({ msg, live }: { msg: Message; live?: LiveState | null
   // 流式期间：工具/思考阶段过程实时展开；一旦进入 responding（最终回复开始流式）
   // 立即折叠过程，只显式显示回复（Cursor 式）；工具恢复（acting）时重新展开。
   // run 终态后：按偏好折叠为摘要行（可回看）。
-  const showProcessInline = live ? live.phase !== 'responding' : !autoCollapse
+  const showProcess = showProcessInline(live ?? null, autoCollapse)
   const lastContentIdx = split.content.length - 1
   return (
     <div className="msg assistant">
@@ -122,7 +125,7 @@ function AssistantMessage({ msg, live }: { msg: Message; live?: LiveState | null
         <span>助手</span>
         {live && <span className="live-bar"><span className="live-dot" />{live.phase}</span>}
       </div>
-      {split.process.length > 0 && (showProcessInline
+      {split.process.length > 0 && (showProcess
         ? split.process.map((p, i) => <div className="part" key={i}><PartView part={p} live={!!live} /></div>)
         : <ProcessCollapse parts={split.process} />)}
       {split.content.map((p, i) => {
@@ -250,7 +253,7 @@ export function Conversation() {
 
   useEffect(() => {
     bodyRef.current?.scrollTo({ top: bodyRef.current.scrollHeight })
-  }, [messages.length, live?.texts, live?.thinking, live?.toolCalls.length, live?.phase, activeHitl.length])
+  }, [messages.length, live?.items, live?.phase, activeHitl.length])
 
   const send = async () => {
     if (!text.trim() && attachmentIds.length === 0) return