feat: improve join request visibility for admins and applicants

- Add prominent pending join request badge on GroupView header
  with pulse animation for admins/owners
- Clicking badge smoothly scrolls to request list with highlight
- Add "My Join Requests" section on Profile page
- Show status (pending/approved/rejected), timestamp, and reject reason
- Add API: getMyJoinRequests() to fetch user's full request history

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/api/groups.ts

@@ -118,6 +118,20 @@ export async function getMyGroupsJoinRequests(): Promise<JoinRequest[]> {
   return result.items as unknown as JoinRequest[]
 }
 
+// 获取当前用户的所有入群申请（包括所有状态）
+export async function getMyJoinRequests(): Promise<JoinRequest[]> {
+  const user = pb.authStore.model
+  if (!user) return []
+
+  const result = await pb.collection('join_requests').getList(1, 50, {
+    filter: `user="${user.id}"`,
+    sort: '-created',
+    expand: 'group',
+    $autoCancel: false
+  })
+  return result.items as unknown as JoinRequest[]
+}
+
 // 审批加入申请
 export async function respondJoinRequest(
   requestId: string,