fix(updater): downgrade manual check failure notice to warning

Manual update-check failures surfaced as red error toasts that read as
an app fault. Add a warning severity to the notice service and use it
in both check entry points alongside a console.warn; automatic checks
and install failures keep their existing behavior.

src/components/setting/setting-verge-advanced.tsx

@@ -54,8 +54,9 @@ const SettingVergeAdvanced = ({ onError: _ }: Props) => {
       } else {
         updateRef.current?.open()
       }
-    } catch (err: any) {
-      showNotice.error(err)
+    } catch (err) {
+      console.warn('update check failed:', err)
+      showNotice.warning(err)
     }
   }