fix: only preserve LoadFailed nav status when URL matches failed URL

The syncWebContentsState guard that preserves LoadFailed status when the
computed status is Success was too broad. It ran on all events including
did-navigate and did-navigate-in-page, not just did-stop-loading. This
meant a guest that navigated to a new working URL could still report the
old LoadFailed status, leaving the unreachable overlay stuck in the UI.

Adding a URL comparison ensures the failure is only preserved when
Electron emits did-stop-loading for the same URL that failed (the
intended case), and clears it when navigation to a different URL
succeeds.

Author: cursoragent

apps/desktop/src/preview/Manager.ts

@@ -1142,7 +1142,9 @@ const makeNativeOperations = Effect.fn("PreviewManager.makeOperations")(function
         // failed guest is no longer "loading", but it has not successfully
         // navigated anywhere. Keep the failure until a new load actually starts.
         const navStatus =
-          current.navStatus.kind === "LoadFailed" && computedNavStatus.kind === "Success"
+          current.navStatus.kind === "LoadFailed" &&
+          computedNavStatus.kind === "Success" &&
+          computedNavStatus.url === current.navStatus.url
             ? current.navStatus
             : computedNavStatus;
         const state: PreviewTabState = {