fix(proxy): sync UI when active provider differs from current setting

Previously, UI sync was triggered only when failover happened (retry count > 1).
This missed cases where the first provider in the failover queue succeeded but
was different from the user's selected provider in settings.

Now we capture the current provider ID at request start and compare it with
the actually used provider. This ensures UI/tray always reflects the real
provider handling requests.

src-tauri/src/proxy/forwarder.rs

@@ -29,6 +29,8 @@ pub struct RequestForwarder {
     failover_manager: Arc<FailoverSwitchManager>,
     /// AppHandle，用于发射事件和更新托盘
     app_handle: Option<tauri::AppHandle>,
+    /// 请求开始时的“当前供应商 ID”（用于判断是否需要同步 UI/托盘）
+    current_provider_id_at_start: String,
 }
 
 impl RequestForwarder {
@@ -40,6 +42,7 @@ impl RequestForwarder {
         current_providers: Arc<RwLock<std::collections::HashMap<String, (String, String)>>>,
         failover_manager: Arc<FailoverSwitchManager>,
         app_handle: Option<tauri::AppHandle>,
+        current_provider_id_at_start: String,
     ) -> Self {
         let mut client_builder = Client::builder();
         if timeout_secs > 0 {
@@ -58,6 +61,7 @@ impl RequestForwarder {
             current_providers,
             failover_manager,
             app_handle,
+            current_provider_id_at_start,
         }
     }
 
@@ -145,7 +149,6 @@ impl RequestForwarder {
         );
 
         let mut last_error = None;
-        let mut failover_happened = false;
         let mut attempted_providers = 0usize;
 
         // 依次尝试每个供应商
@@ -167,9 +170,6 @@ impl RequestForwarder {
             let used_half_open_permit = permit.used_half_open_permit;
 
             attempted_providers += 1;
-            if attempted_providers > 1 {
-                failover_happened = true;
-            }
 
             log::info!(
                 "[{}] 尝试 {}/{} - 使用Provider: {} (sort_index: {})",
@@ -228,16 +228,18 @@ impl RequestForwarder {
                         let mut status = self.status.write().await;
                         status.success_requests += 1;
                         status.last_error = None;
-                        if failover_happened {
+                        let should_switch =
+                            self.current_provider_id_at_start.as_str() != provider.id.as_str();
+                        if should_switch {
                             status.failover_count += 1;
                             log::info!(
-                                "[{}] 故障转移成功！切换到 Provider: {} (耗时: {}ms)",
+                                "[{}] 代理目标已切换到 Provider: {} (耗时: {}ms)",
                                 app_type_str,
                                 provider.name,
                                 latency
                             );
 
-                            // 异步触发供应商切换，更新 UI 和托盘菜单
+                            // 异步触发供应商切换，更新 UI/托盘，并把“当前供应商”同步为实际使用的 provider
                             let fm = self.failover_manager.clone();
                             let ah = self.app_handle.clone();
                             let pid = provider.id.clone();