feat: add periodic tray menu refresh and normalize tunnel metrics field names

Add background task to refresh tray menu every 5 seconds to keep status display current. Add RawTunnelMetrics type and normalizeTunnelMetrics helper to handle both snake_case and camelCase field names from backend responses. Update refreshTunnelMetrics to normalize metrics before setting state and explicitly cast active status to boolean.

desktop-client/src-tauri/src/lib.rs

@@ -665,6 +665,14 @@ pub fn run() {
             });
             refresh_tray_menu(app.handle());
 
+            let app_handle = app.handle().clone();
+            tauri::async_runtime::spawn(async move {
+                loop {
+                    refresh_tray_menu(&app_handle);
+                    tauri::async_runtime::sleep(std::time::Duration::from_secs(5)).await;
+                }
+            });
+
             Ok(())
         })
         .on_window_event(|window, event| match event {

desktop-client/src/App.tsx

@@ -17,6 +17,14 @@ type TunnelMetrics = {
   txBytes: number;
 };
 
+type RawTunnelMetrics = {
+  active?: boolean;
+  rxBytes?: number;
+  txBytes?: number;
+  rx_bytes?: number;
+  tx_bytes?: number;
+};
+
 function formatInvokeError(err: unknown, fallback: string) {
   if (typeof err === "string" && err.trim().length > 0) {
     return err;
@@ -67,6 +75,14 @@ function formatDataSize(bytes: number) {
   return `${value >= 100 || unitIndex === 0 ? value.toFixed(0) : value.toFixed(1)} ${units[unitIndex]}`;
 }
 
+function normalizeTunnelMetrics(value: RawTunnelMetrics | null | undefined): TunnelMetrics {
+  return {
+    active: Boolean(value?.active),
+    rxBytes: Number(value?.rxBytes ?? value?.rx_bytes ?? 0),
+    txBytes: Number(value?.txBytes ?? value?.tx_bytes ?? 0)
+  };
+}
+
 export function App() {
   const [serverUrl, setServerUrl] = useState("http://localhost");
   const [username, setUsername] = useState("");
@@ -84,14 +100,14 @@ export function App() {
 
   async function refreshTunnelMetrics() {
     try {
-      const value = await invoke<TunnelMetrics>("tunnel_metrics");
+      const value = normalizeTunnelMetrics(await invoke<RawTunnelMetrics>("tunnel_metrics"));
       setMetrics(value);
       setConnected(value.active);
     } catch {
       try {
         const active = await invoke<boolean>("tunnel_status");
         setConnected(active);
-        setMetrics((current) => ({ ...current, active }));
+        setMetrics((current) => ({ ...current, active: Boolean(active) }));
       } catch {
         setMetrics({ active: false, rxBytes: 0, txBytes: 0 });
         setConnected(false);