desktop: open in file manager fails with Desktop IPC handler failed #50632

Summary

The desktop app's "open in file manager" action fails with the toast 请求失败 / Desktop IPC handler failed. Windows File Explorer never opens.

Environment

• opencode version: 2.0.13 (desktop app; bundled opencode-cli 2.0.13)
• OS: Windows 10.0.26200.9457 (win32 x64)
• Terminal: Unavailable: not applicable (desktop app)
• Shell: Unavailable: not applicable (desktop app)
• Install/channel: latest (built-in updater reports "up-to-date")
• Active plugins: none

Reproduction

1. In the desktop app, trigger the "open in file manager" action on a file or folder.
2. The toast 请求失败 / Desktop IPC handler failed appears; Explorer does not open.

Expected Behavior

Windows Explorer opens with the target file/folder selected.

Actual Behavior

Toast: 请求失败 / Desktop IPC handler failed. No window opens. Reproducible for both C:\Windows (ASCII) and paths with non-ASCII names.

Additional Context

• Desktop logs (%APPDATA%\ai.opencode.desktop\logs\<timestamp>\{main,renderer,crash}.log) show a normal startup and no IPC exception around the failure time; renderer.log only contains ResizeObserver loop completed with undelivered notifications warnings.
• main.log confirms: version 2.0.13, updater reports "Update for version 2.0.13 is not available", background service ready at http://127.0.0.1:49374.
• Workaround that works: run explorer.exe <path> (or explorer /select,<file>) from a terminal/agent shell.
• Related: clicking a folder in the app also fails separately (fs/read 500 Path is not a file) — filed as a separate issue.