Desktop 1.18.13: no completion/attention sound — @opentui audio fails under Node runtime

Environment

• OpenCode Desktop: 1.18.13 (Windows x64, @opencode-aidesktop)
• OS: Windows 11
• Previous behavior: completion sound worked on earlier desktop versions (~1 week ago)

Problem

No "session done" / attention sound plays in the desktop app after a response finishes. Attention config is fully enabled in tui.json (enabled: true, sound: true, volume: 0.7, custom ./sounds/done.wav which is valid and plays fine via Windows SoundPlayer). Nothing in the config changed.

Root cause (confirmed by direct reproduction)

The desktop app runs on a Node runtime (no Bun global; e.g. Bun-using plugins throw Bun is not defined). OpenCode's attention sounds go through @opentui/core, which needs Bun FFI to load its native Zig audio library. Under Node, Audio.create() throws, so getAudio() in packages/tui/src/audio.ts returns null and all sounds fail silently (only console.debug logs, not visible in the info log).

Reproduction (same package, two runtimes):

const { Audio } = await import("@opentui/core")
Audio.create({ autoStart: false })
// Node 22: throws "Failed to resolve the native audio library"
// Bun 1.3: works fine

Expected

The desktop app should play attention/completion sounds. Options: bundle a Node-compatible audio backend, or load the native library without depending on Bun FFI when running under Node.

Impact

No sound feedback on session completion / errors / permission prompts in the desktop app (Windows). Related: the CLI (Bun runtime) is unaffected.