优化: AI Chat 渲染与无障碍 + 文件查看 + 同步 IO 收口

- 渲染: 结果/过程分离(气泡只放最终结果,过程轮叙述+工具卡收进轨迹卡默认收起可展开——治『流式后正文消失』且不再 N 气泡打扰)
- 渲染 P0: v-memo 定向 dep(只有真正渲染流式块的 item 失效,其余取占位) + renderItems 桶 memo(签名覆盖全消费输入,item 引用稳定) + 指纹 watch 降为 O(1) toolEpoch
- TopBar 三处 O(n) messages computed 合并单次遍历;md 缓存改有界 LRU(除满即全清抖动);useTurnTrace 补 never 穷尽 + default;MessageItem 模板去重
- 无障碍(四批累计): 可点容器键盘化(含 role/tabindex/keydown/aria-expanded) + icon-only aria-label 约 60 处 + 装饰图标 aria-hidden + 52 个滚动容器 overscroll-behavior:contain + 设置开关聚焦可见环 + outline 零补偿站点补 :focus-visible
- UX 走查项: 灵感 IDEA-10/11、知识 KNOW-6/7/9、项目详情 O8、审计 SA-4、设置 SA-6/26/27/28(脏表单/冗余 save/clamp/删除二次确认)
- 文件查看专项: 切工程状态残留 F5/F6、FileTree 去重与展开反馈 F7/F15/F17、切文件头部残留 F18、R 状态着色 F19;FilePreview diff 文件头(---/+++)误当增删渲染修复 + 大纲行高亮死样式修复 + 图片失败文案 i18n 化
- 同步 IO 收口(异步上下文内阻塞): unattended 看板读写改 tokio::fs、fetch_url 探活改 spawn_blocking、http/generate_image 清理改 tokio::fs
- 子代理 P3 批量: 任务书钉扎上限/截断文案区分父子语境/环境画像日期/temperature 可覆盖/model 回退上报/lang 透传
- crate 清理: df-execute·df-types 注释与格式、df-ideas 过时注释、df-nodes subflow 夸大描述、df-project 死变量

src/components/ai/TopBar.vue

@@ -209,7 +209,7 @@
             <span v-if="g.status === 'active'" class="ai-goal-dot"></span>
             <span v-else class="ai-goal-check">✓</span>
             <span class="ai-goal-text">{{ g.text }}</span>
-            <button class="ai-goal-remove" @click.stop="removeGoal(i)">×</button>
+            <button class="ai-goal-remove" @click.stop="removeGoal(i)" :aria-label="$t('common.delete')">×</button>
           </div>
         </div>
       </Transition>
@@ -222,7 +222,7 @@
       </button>
       <Transition name="ai-pop">
         <div v-if="historyExpanded" class="ai-history-inline-list">
-          <div v-for="h in historyMsgs" :key="h.id" class="ai-history-inline-item" @click="scrollToMessage(h.id)">
+          <div v-for="h in historyMsgs" :key="h.id" class="ai-history-inline-item" role="button" tabindex="0" @click="scrollToMessage(h.id)" @keydown.enter.prevent="scrollToMessage(h.id)" @keydown.space.prevent="scrollToMessage(h.id)">
             <span class="ai-history-index">{{ h.num }}</span>
             <span class="ai-history-text">{{ h.text }}</span>
             <span class="ai-history-time">{{ h.time }}</span>
@@ -238,7 +238,7 @@
       </button>
       <Transition name="ai-pop">
         <div v-if="summaryExpanded" class="ai-summary-inline-list">
-          <div v-for="(s, i) in summaryMsgs" :key="i" class="ai-summary-inline-item" @click="scrollToMessage(s.id)">
+          <div v-for="(s, i) in summaryMsgs" :key="i" class="ai-summary-inline-item" role="button" tabindex="0" @click="scrollToMessage(s.id)" @keydown.enter.prevent="scrollToMessage(s.id)" @keydown.space.prevent="scrollToMessage(s.id)">
             <span class="ai-summary-label">{{ $t('aiChat.compressedSummaryLabel') }} #{{ summaryMsgs.length - i }}</span>
             <p class="ai-summary-preview">{{ s.text }}</p>
           </div>
@@ -309,7 +309,7 @@ import { aiApi } from '../../api/ai'
 import { pendingTaskProgress } from '../../composables/ai/useAiPendingState'
 import { convRounds } from '../../composables/ai/aiShared'
 import { switchConversation } from '../../composables/ai/useAiConversations'
-import type { AiMessage, ModelConfig, GoalEntry } from '../../api/types'
+import type { ModelConfig, GoalEntry } from '../../api/types'
 
 defineProps<{
   /** 分离窗口模式(嵌入 vs 分离决定顶部按钮组) */
@@ -595,6 +595,7 @@ const goalsExpanded = ref(false)
 
 // ── 📋 历史消息(当前会话 user 消息列表) ──
 interface HistoryItem { id: string; text: string; time: string; num: number }
+interface SummaryItem { id: string; text: string }
 /** 时间显示:今日 HH:mm / 昨天 HH:mm / MM-DD HH:mm */
 function fmtTime(ts: number): string {
   const d = new Date(ts)
@@ -616,17 +617,45 @@ function fmtTime(ts: number): string {
 }
 const MAX_HISTORY = 20
 const MAX_CHARS = 80
-const historyMsgs = computed<HistoryItem[]>(() => {
-  const allUserMsgs = store.state.messages
-    .filter((m): m is AiMessage & { timestamp: number } => m.role === 'user' && !!m.content && !!m.timestamp)
-    .map((m, idx) => ({
-      id: m.id,
-      text: m.content.length > MAX_CHARS ? m.content.slice(0, MAX_CHARS) + '…' : m.content,
-      time: fmtTime(m.timestamp),
-      num: idx + 1,
-    }))
-  return allUserMsgs.slice(-MAX_HISTORY).reverse()
+// 单次遍历 messages,一次产出「历史(user 消息)/摘要(system 消息)/项目名」三路派生,
+// 替代原先三处 computed 各自全量扫描(historyMsgs/summaryMsgs/contextInfo)。
+// 三路的筛选条件、收集顺序、截断与反转语义与拆分前逐项一致。
+const msgDerived = computed(() => {
+  const history: HistoryItem[] = []
+  const summaries: SummaryItem[] = []
+  const projectLabels = new Set<string>()
+  for (const m of store.state.messages) {
+    if (m.role === 'user') {
+      // 项目名收集只认 user 的 mentionSpans(不设 content/timestamp 门槛),
+      // 与原 contextInfo 的独立遍历同条件,故与下面的历史筛选互不干扰。
+      if (m.mentionSpans?.length) {
+        for (const sp of m.mentionSpans) {
+          if (sp.kind === 'project' && sp.label) projectLabels.add(sp.label)
+        }
+      }
+      if (m.content && m.timestamp) {
+        history.push({
+          id: m.id,
+          text: m.content.length > MAX_CHARS ? m.content.slice(0, MAX_CHARS) + '…' : m.content,
+          time: fmtTime(m.timestamp),
+          num: history.length + 1,
+        })
+      }
+    } else if (m.role === 'system' && m.content) {
+      summaries.push({
+        id: m.id,
+        text: m.content.length > 120 ? m.content.slice(0, 120) + '…' : m.content,
+      })
+    }
+  }
+  return {
+    history: history.slice(-MAX_HISTORY).reverse(),
+    summaries,
+    projectNames: Array.from(projectLabels).join(', '),
+  }
 })
+const historyMsgs = computed<HistoryItem[]>(() => msgDerived.value.history)
+const summaryMsgs = computed<SummaryItem[]>(() => msgDerived.value.summaries)
 const historyExpanded = ref(false)
 
 /** 点击历史消息项 → 滚动定位到对应的消息气泡 */
@@ -672,15 +701,7 @@ function onBottomToolsClickOutside(e: MouseEvent) {
   }
 }
 // ── 📄 上下文摘要(压缩/归档的系统消息) ──
-interface SummaryItem { id: string; text: string }
-const summaryMsgs = computed<SummaryItem[]>(() => {
-  return store.state.messages
-    .filter(m => m.role === 'system' && !!m.content)
-    .map(m => ({
-      id: m.id,
-      text: m.content.length > 120 ? m.content.slice(0, 120) + '…' : m.content,
-    }))
-})
+// SummaryItem 类型与 summaryMsgs 派生已上移至历史区(与 historyMsgs 共享单次遍历)。
 const summaryExpanded = ref(false)
 
 // ── L3 完整上下文 ──
@@ -707,22 +728,11 @@ function togglePanel(panel: 'goals' | 'history' | 'summary' | 'context' | 'runni
 const contextInfo = computed<ContextInfo>(() => {
   const convId = store.state.activeConversationId
   const conv = convId ? store.state.conversations.find(c => c.id === convId) : undefined
-  // 从所有 user 消息中收集 mentionSpans(kind === 'project'),去重
-  const projectLabels = new Set<string>()
-  for (const m of store.state.messages) {
-    if (m.role === 'user' && m.mentionSpans?.length) {
-      for (const sp of m.mentionSpans) {
-        if (sp.kind === 'project' && sp.label) {
-          projectLabels.add(sp.label)
-        }
-      }
-    }
-  }
   return {
     goals: conv?.pinned_goals ?? [],
-    summaryCount: summaryMsgs.value.length,
+    summaryCount: msgDerived.value.summaries.length,
     osInfo: 'Windows 11 / PowerShell',
-    projectNames: Array.from(projectLabels).join(', ') || t('aiChat.none'),
+    projectNames: msgDerived.value.projectNames || t('aiChat.none'),
   }
 })
 
@@ -916,6 +926,8 @@ onBeforeUnmount(() => {
   outline: none;
   cursor: pointer;
 }
+/* 聚焦可见环:聚焦态无边框变化,且 scoped 选择器特异性高于全局 :focus-visible 兜底,须就地补环,仅键盘聚焦显示 */
+.ai-model-select:focus-visible { outline: 2px solid var(--df-accent); outline-offset: 1px; }
 .ai-model-select--compact {
   max-width: 130px;
 }