feat: onShow静默刷新 + 群组预算双显 + TransactionItem优化

onShow 静默刷新（首次有loading，后续静默）:
- budget: 添加 initialLoaded 守卫，避免首次双重请求
- profile: 添加 onShow 刷新概览/预算/账单/群组
- group-manage: 添加 onShow 刷新群组列表
- category-manage: 添加 onShow 刷新分类列表
- add: 添加 onShow 刷新分类（可能新增了分类）

群组模式预算双显:
- 服务端 GET /budget 群组模式额外返回 myAmount（本人预算）
- 客户端 Budget 类型添加 myAmount 字段
- 预算页群组模式：群组总预算卡片（只读）+ 我的预算卡片（可编辑）
- 个人模式保持原样

TransactionItem 群组模式优化:
- 主图标始终显示分类图标（不再显示创建者头像）
- 他人记录在昵称旁显示小头像（28rpx圆形）

server/src/routes/budget.ts

@@ -15,7 +15,7 @@ router.get('/', async (req: AuthRequest, res: Response) => {
     const group_id = req.query.group_id as string | undefined
 
     if (group_id && group_id !== 'null') {
-      // 群组视图：所有成员的预算总和
+      // 群组视图：所有成员的预算总和 + 当前用户个人预算
       const [memberCheck] = await pool.query(
         'SELECT id FROM group_members WHERE group_id = ? AND user_id = ?',
         [group_id, req.userId]
@@ -24,15 +24,20 @@ router.get('/', async (req: AuthRequest, res: Response) => {
         return res.status(403).json({ code: 40300, message: '无权访问此群组' })
       }
 
-      const [rows] = await pool.query(
+      const [groupRows] = await pool.query(
         `SELECT COALESCE(SUM(amount), 0) as amount, month
          FROM budgets
          WHERE user_id IN (SELECT user_id FROM group_members WHERE group_id = ?) AND month = ?
          GROUP BY month`,
         [group_id, month]
       )
-      const budget = (rows as any[])[0] || { amount: 0, month }
-      res.json({ code: 0, data: budget })
+      const [myRows] = await pool.query(
+        'SELECT COALESCE(amount, 0) as amount FROM budgets WHERE user_id = ? AND month = ?',
+        [req.userId, month]
+      )
+      const groupBudget = (groupRows as any[])[0] || { amount: 0, month }
+      const myAmount = (myRows as any[])[0]?.amount || 0
+      res.json({ code: 0, data: { amount: groupBudget.amount, myAmount, month } })
     } else {
       // 个人视图
       const [rows] = await pool.query(
@@ -40,6 +45,9 @@ router.get('/', async (req: AuthRequest, res: Response) => {
         [req.userId, month]
       )
       const budget = (rows as any[])[0] || null
+      if (budget) {
+        budget.myAmount = budget.amount
+      }
       res.json({ code: 0, data: budget })
     }
   } catch (err) {