[Bug] USB Serial Listener Freezes UI on Startup

Bug Description
When Claude Code starts to listen to USB serial, the entire UI freezes (Ctrl+C no longer works, no updates, completely frozen).

Environment Info

• Platform: darwin
• Terminal: Apple_Terminal
• Version: 2.1.17
• Feedback ID: d8b38ee8-8dd9-4852-a0b5-714ceea7af4d

Errors

[{"error":"Error: ENOENT: no such file or directory, scandir '/Library/Application Support/ClaudeCode/.claude/skills'\n    at readdirSync (unknown)\n    at <anonymous> (/$bunfs/root/claude:12:1903)\n    at vW (/$bunfs/root/claude:11:35097)\n    at readdirSync (/$bunfs/root/claude:12:1864)\n    at y2R (/$bunfs/root/claude:1479:380)\n    at y2R (/$bunfs/root/claude:1479:1350)\n    at <anonymous> (/$bunfs/root/claude:1479:4440)\n    at <anonymous> (/$bunfs/root/claude:1479:5171)\n    at A (/$bunfs/root/claude:11:7244)\n    at pX8 (/$bunfs/root/claude:4784:4342)","timestamp":"2026-02-02T13:12:13.704Z"},{"error":"Error: ENOENT: no such file or directory, scandir '/Users/vidklopcic/.claude/skills'\n    at readdirSync (unknown)\n    at <anonymous> (/$bunfs/root/claude:12:1903)\n    at vW (/$bunfs/root/claude:11:35097)\n    at readdirSync (/$bunfs/root/claude:12:1864)\n    at y2R (/$bunfs/root/claude:1479:380)\n    at y2R (/$bunfs/root/claude:1479:1350)\n    at <anonymous> (/$bunfs/root/claude:1479:4483)\n    at <anonymous> (/$bunfs/root/claude:1479:5171)\n    at A (/$bunfs/root/claude:11:7244)\n    at pX8 (/$bunfs/root/claude:4784:4342)","timestamp":"2026-02-02T13:12:13.704Z"},{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/vidklopcic/.local/share/claude/versions/2.1.17 (expected in multi-process scenarios)\n    at RYR (/$bunfs/root/claude:3902:2091)\n    at GbA (/$bunfs/root/claude:3902:1202)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-02-02T13:12:13.721Z"},{"error":"Error: ENOENT: no such file or directory, scandir '/Library/Application Support/ClaudeCode/.claude/skills'\n    at readdirSync (unknown)\n    at <anonymous> (/$bunfs/root/claude:12:1903)\n    at vW (/$bunfs/root/claude:11:35097)\n    at readdirSync (/$bunfs/root/claude:12:1864)\n    at y2R (/$bunfs/root/claude:1479:380)\n    at y2R (/$bunfs/root/claude:1479:1350)\n    at <anonymous> (/$bunfs/root/claude:1479:4440)\n    at <anonymous> (/$bunfs/root/claude:1479:5171)\n    at A (/$bunfs/root/claude:11:7244)\n    at pX8 (/$bunfs/root/claude:4784:4342)","timestamp":"2026-02-02T13:12:14.652Z"},{"error":"Error: ENOENT: no such file or directory, scandir '/Users/vidklopcic/.claude/skills'\n    at readdirSync (unknown)\n    at <anonymous> (/$bunfs/root/claude:12:1903)\n    at vW (/$bunfs/root/claude:11:35097)\n    at readdirSync (/$bunfs/root/claude:12:1864)\n    at y2R (/$bunfs/root/claude:1479:380)\n    at y2R (/$bunfs/root/claude:1479:1350)\n    at <anonymous> (/$bunfs/root/claude:1479:4483)\n    at <anonymous> (/$bunfs/root/claude:1479:5171)\n    at A (/$bunfs/root/claude:11:7244)\n    at pX8 (/$bunfs/root/claude:4784:4342)","timestamp":"2026-02-02T13:12:14.652Z"}]