feat: 账号测试状态持久化、分页选择器、点击账号名复制

- Account 结构加 TestStatus 字段，测试后写入 config.json
- listAccounts 接口返回 test_status，前端根据结果显示红/绿/黄状态点
- 分页选择器支持 10/20/50/100/500/1000/2000/5000
- 点击账号名自动复制到剪贴板，hover 显示复制图标，复制后显示绿色对勾

internal/config/config.go

@@ -18,10 +18,11 @@ type Config struct {
 }
 
 type Account struct {
-	Email    string `json:"email,omitempty"`
-	Mobile   string `json:"mobile,omitempty"`
-	Password string `json:"password,omitempty"`
-	Token    string `json:"token,omitempty"`
+	Email      string `json:"email,omitempty"`
+	Mobile     string `json:"mobile,omitempty"`
+	Password   string `json:"password,omitempty"`
+	Token      string `json:"token,omitempty"`
+	TestStatus string `json:"test_status,omitempty"`
 }
 
 type CompatConfig struct {

internal/config/store.go

@@ -97,6 +97,18 @@ func (s *Store) FindAccount(identifier string) (Account, bool) {
 	return Account{}, false
 }
 
+func (s *Store) UpdateAccountTestStatus(identifier, status string) error {
+	identifier = strings.TrimSpace(identifier)
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	idx, ok := s.findAccountIndexLocked(identifier)
+	if !ok {
+		return errors.New("account not found")
+	}
+	s.cfg.Accounts[idx].TestStatus = status
+	return s.saveLocked()
+}
+
 func (s *Store) UpdateAccountToken(identifier, token string) error {
 	identifier = strings.TrimSpace(identifier)
 	s.mu.Lock()