refine: 缓存的 AI 摘要默认折叠，点击展开

- aiExpanded ref: 缓存加载=false, 新生成=true
- 标题栏可点击切换折叠/展开
- 折叠态显示 ▶ + '点击展开' 提示
- 展开态显示 ▼ + 复制按钮
- 卡片边框折叠时降为 warm-border

frontend/src/views/desktop/WeeklyReport.vue

@@ -18,6 +18,7 @@ const aiSummary = ref('')
 const aiError = ref('')
 const aiCached = ref(false)
 const aiCreatedAt = ref('')
+const aiExpanded = ref(false)
 const activeTab = ref('visits')
 const filterManagerId = ref('')
 const filterCustomerId = ref('')
@@ -125,6 +126,7 @@ async function generateAISummary() {
     aiSummary.value = res.data.summary
     aiCached.value = !!res.data.cached
     aiCreatedAt.value = res.data.created_at || ''
+    aiExpanded.value = true
   } catch (e: any) {
     const detail = e.response?.data?.detail || 'AI 摘要生成失败，请检查 AI 服务配置或稍后重试'
     aiError.value = detail
@@ -253,26 +255,29 @@ const notesByDate = computed(() => {
     </el-card>
 
     <!-- ═══ AI Summary Panel ═══ -->
-    <el-card v-if="aiSummary || aiLoading || aiError" class="ai-summary-card">
+    <el-card v-if="aiSummary || aiLoading || aiError" class="ai-summary-card" :class="{ 'ai-summary-card--collapsed': !aiExpanded && aiSummary }">
       <template #header>
-        <div class="ai-header">
+        <div class="ai-header" @click="aiSummary && (aiExpanded = !aiExpanded)" :style="aiSummary ? 'cursor:pointer' : ''">
           <div class="ai-header-left">
+            <span v-if="aiSummary" class="ai-expand-arrow">{{ aiExpanded ? '▼' : '▶' }}</span>
             <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" style="color: var(--gold); margin-right:6px">
               <polygon points="13 2 3 14 12 14 11 22 21 10 12 10 13 2"></polygon>
             </svg>
             <span class="ai-header-title">AI 周报摘要</span>
-            <span v-if="aiCached && aiCreatedAt" class="ai-header-hint">生成于 {{ new Date(aiCreatedAt).toLocaleString('zh-CN') }} · 已缓存</span>
+            <span v-if="aiSummary && !aiExpanded && aiCached" class="ai-header-hint">生成于 {{ new Date(aiCreatedAt).toLocaleString('zh-CN') }} · 已缓存 · 点击展开</span>
+            <span v-else-if="aiSummary && aiExpanded && aiCached && aiCreatedAt" class="ai-header-hint">生成于 {{ new Date(aiCreatedAt).toLocaleString('zh-CN') }} · 已缓存</span>
+            <span v-else-if="aiLoading" class="ai-header-hint">正在分析...</span>
             <span v-else class="ai-header-hint">基于本周拜访数据自动生成，仅供参考</span>
           </div>
-          <div class="ai-header-actions">
+          <div class="ai-header-actions" @click.stop>
-            <el-button v-if="aiSummary" size="small" text @click="copySummary">
+            <el-button v-if="aiSummary && aiExpanded" size="small" text @click="copySummary">
               <svg width="13" height="13" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" style="margin-right:3px">
                 <rect x="9" y="9" width="13" height="13" rx="2" ry="2"></rect>
                 <path d="M5 15H4a2 2 0 0 1-2-2V4a2 2 0 0 1 2-2h9a2 2 0 0 1 2 2v1"></path>
               </svg>
               复制
             </el-button>
-            <el-button size="small" text @click="aiSummary = ''; aiError = ''">
+            <el-button size="small" text @click="aiSummary = ''; aiError = ''; aiExpanded = false">
               <svg width="13" height="13" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
                 <line x1="18" y1="6" x2="6" y2="18"></line>
                 <line x1="6" y1="6" x2="18" y2="18"></line>
@@ -287,7 +292,7 @@ const notesByDate = computed(() => {
       <div v-else-if="aiError" class="ai-error">
         {{ aiError }}
       </div>
-      <div v-else class="ai-content" v-html="renderMarkdown(aiSummary)"></div>
+      <div v-else-if="aiExpanded" class="ai-content" v-html="renderMarkdown(aiSummary)"></div>
     </el-card>
 
     <!-- Tabs -->
@@ -402,9 +407,19 @@ const notesByDate = computed(() => {
 .ai-summary-card {
   margin-bottom: 16px;
   border-color: var(--gold);
+  transition: border-color 0.2s;
+}
+.ai-summary-card--collapsed {
+  border-color: var(--warm-border);
 }
 .ai-header {
   display: flex; justify-content: space-between; align-items: center;
+  user-select: none;
+}
+.ai-expand-arrow {
+  font-size: 10px; color: var(--gold);
+  width: 14px; flex-shrink: 0;
+  transition: transform 0.2s;
 }
 .ai-header-left {
   display: flex; align-items: center;