feat: 更新MainFeature以优化用户状态管理

- 在MainFeature中增强用户状态管理逻辑，确保仅在用户切换时重置首次加载状态。
- 更新MeFeature的uid处理逻辑，提升用户体验与状态一致性。

yana/Features/MainFeature.swift

@@ -59,7 +59,10 @@ struct MainFeature: Reducer {
                 state.selectedTab = tab
                 state.navigationPath = []
                 if tab == .other, let uidStr = state.accountModel?.uid, let uid = Int(uidStr), uid > 0 {
-                    state.me = MeFeature.State(uid: uid)
+                    if state.me.uid != uid {
+                        state.me.uid = uid
+                        state.me.isFirstLoad = true // 仅当用户切换时才重置首次加载
+                    }
                     return .send(.me(.onAppear))
                 }
                 return .none