fix: updater download — pass full UpdateInfo object, not just version string

DownloadUpdate expects *UpdateInfo (with downloadUrl), not a version string.
Frontend was passing latestVersion which caused a silent deserialization failure.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/common/StatusBar.vue

@@ -117,7 +117,7 @@ async function handleUpdate(): Promise<void> {
   try {
     const path = await Call.ByName(
       "github.com/vstockwell/wraith/internal/updater.UpdateService.DownloadUpdate",
-      updateInfo.value.latestVersion
+      updateInfo.value
     ) as string;
     await Call.ByName(
       "github.com/vstockwell/wraith/internal/updater.UpdateService.ApplyUpdate",