feat: 竞赛分组页面项目支持折叠，默认收起

- 点击项目头部可展开/收起队伍列表
- 默认所有项目收起，方便管理多个项目
- 添加展开图标指示当前状态

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/views/martial/schedule/index.vue

@@ -73,9 +73,14 @@
 
           <!-- 项目卡片列表 -->
           <div v-for="(group, groupIndex) in filteredCompetitionGroups" :key="group.id" class="project-card">
-            <!-- 项目头部 -->
-            <div class="project-header">
+            <!-- 项目头部 - 可点击展开 -->
+            <div class="project-header" :class="{ 'project-header-collapsed': !isProjectExpanded(group.id) }" @click="toggleProjectExpand(group.id)">
               <div class="project-info">
+                <!-- 展开图标 -->
+                <span class="project-expand-icon">
+                  <el-icon v-if="isProjectExpanded(group.id)"><ArrowDown /></el-icon>
+                  <el-icon v-else><ArrowRight /></el-icon>
+                </span>
                 <span class="project-index">{{ groupIndex + 1 }}、</span>
                 <span class="project-title">{{ group.title }}</span>
                 <span class="project-meta">{{ group.type }}</span>
@@ -83,7 +88,7 @@
                 <span class="project-meta">{{ group.items?.length || 0 }}组</span>
                 <span class="project-meta">{{ group.code }}</span>
               </div>
-              <div class="project-actions">
+              <div class="project-actions" @click.stop>
                 <el-popover
                   placement="bottom"
                   :width="200"
@@ -111,8 +116,8 @@
               </div>
             </div>
 
-            <!-- 队伍列表 -->
-            <div class="team-list">
+            <!-- 队伍列表 - 可折叠 -->
+            <div v-if="isProjectExpanded(group.id)" class="team-list">
               <div
                 v-for="(team, teamIndex) in groupItemsByTeam(group.items)"
                 :key="team.id"
@@ -394,7 +399,8 @@ export default {
       // 异常组相关
       exceptionDialogVisible: false,
       exceptionList: [], // 异常参赛人员列表
-      expandedTeams: {} // 展开的队伍 { 'groupId-teamId': true }
+      expandedTeams: {}, // 展开的队伍 { 'groupId-teamId': true }
+      expandedProjects: {} // 展开的项目 { 'groupId': true }，默认收起
     }
   },
   computed: {
@@ -460,6 +466,22 @@ export default {
     }
   },
   methods: {
+    // 检查项目是否展开
+    isProjectExpanded(groupId) {
+      return this.expandedProjects[groupId] === true
+    },
+
+    // 切换项目展开状态
+    toggleProjectExpand(groupId) {
+      if (this.expandedProjects[groupId]) {
+        delete this.expandedProjects[groupId]
+      } else {
+        this.expandedProjects[groupId] = true
+      }
+      // 触发响应式更新
+      this.expandedProjects = { ...this.expandedProjects }
+    },
+
     // 检查队伍是否展开
     isTeamExpanded(groupId, teamId) {
       const key = groupId + '-' + teamId
@@ -1280,12 +1302,30 @@ export default {
           padding: 12px 16px;
           background: #fafafa;
           border-bottom: 1px solid #e4e7ed;
+          cursor: pointer;
+          transition: background-color 0.2s;
+
+          &:hover {
+            background: #f0f0f0;
+          }
+
+          &.project-header-collapsed {
+            border-bottom: none;
+          }
 
           .project-info {
             display: flex;
             align-items: center;
             gap: 12px;
 
+            .project-expand-icon {
+              width: 20px;
+              color: #909399;
+              display: flex;
+              align-items: center;
+              justify-content: center;
+            }
+
             .project-index {
               font-weight: 600;
               color: #e6a23c;