feat(dac-wizard): add DAC capabilities query from PipeWire/PulseAudio
Backend (Rust):
- Add query_dac_capabilities command that queries pw-cli and pactl
- Returns supported sample rates, formats, channels, and device description
- Parses both PipeWire and PulseAudio outputs for maximum compatibility
Frontend (Svelte):
- Add "Query DAC Capabilities" button in detect-dac step
- Display detected sample rates, formats, channels
- Show disclaimer about checking manufacturer docs if values don't match
- Add translations for query UI (EN/ES/FR/DE)