fix: add audio device probe and afplay timeout to VoiceServer

[MarvinDontPanic]

Summary

Two related reliability fixes for VoiceServer on macOS:

• Audio device probe at startup: Plays a near-silent system sound (Tink.aiff at 1% volume) with a 3-second timeout. If afplay hangs (no output device, virtual audio, or running under launchd without an audio session), all voice playback is disabled for the session rather than hanging the server
• afplay timeout per-clip: 10-second timeout on each playback call with a settled-flag pattern to prevent resolve/reject races. Most TTS clips are 1-3s, so 10s catches hung audio devices without cutting off legitimate long utterances

Problem

Without these fixes, afplay hangs indefinitely when no audio output device is available, blocking the notification server's /notify endpoint. This commonly happens when:

• Running VoiceServer as a system service (launchd) without an audio session
• Virtual audio devices that accept connections but don't produce output
• Headless environments or SSH sessions

File Changed

Releases/v4.0.3/.claude/VoiceServer/server.ts

Test plan

• Start VoiceServer with working audio → probe reports "output device available", playback works
• Start VoiceServer without audio output → probe reports "no usable output device", /notify returns success but skips playback
• Send a notification during audio device disconnect → timeout fires after 10s instead of hanging

🤖 Generated with Claude Code