fix: idempotent conv-key upsert + guard tauri-only notification calls

apps/desktop/src/lib/osNotify.ts

@@ -4,6 +4,8 @@ import {
   sendNotification,
 } from '@tauri-apps/plugin-notification';
 
+import { isTauriRuntime } from './globalShortcut';
+
 // Tracks whether permission has already been requested this session so we
 // don't spam the OS prompt. Actual permission state lives in the OS.
 let permissionChecked = false;
@@ -12,6 +14,11 @@ let permissionGranted = false;
 export async function ensureNotificationPermission(): Promise<boolean> {
   if (permissionChecked) return permissionGranted;
   permissionChecked = true;
+  if (!isTauriRuntime()) {
+    // Web preview / Chrome — Tauri notification plugin not available.
+    permissionGranted = false;
+    return false;
+  }
   try {
     let granted = await isPermissionGranted();
     if (!granted) {
@@ -20,7 +27,6 @@ export async function ensureNotificationPermission(): Promise<boolean> {
     }
     permissionGranted = granted;
   } catch (err: unknown) {
-    // Not running under Tauri (e.g. web preview) — fall back silently.
     permissionGranted = false;
     console.warn('notification permission check failed', err);
   }
@@ -40,6 +46,7 @@ interface NotifyOpts {
 
 export async function notify({ title, body, force = false }: NotifyOpts): Promise<void> {
   if (!force && isAppFocused()) return;
+  if (!isTauriRuntime()) return;
   const granted = await ensureNotificationPermission();
   if (!granted) return;
   try {