Initial implementation: Bordanlage boat onboard system

Complete multiroom audio + navigation dashboard:
- Docker stack: SignalK, Snapcast (4 zones), librespot, shairport-sync, Mopidy, Jellyfin, Portainer
- React 18 + Vite dashboard with nautical dark theme
- Full mock system (SignalK NMEA simulation, Snapcast zones, Mopidy player)
- Real API clients for all services with reconnect logic
- SVG instruments: Compass, WindRose, Gauge, DepthSounder, SpeedLog
- Pages: Overview, Navigation, Audio (zones/radio/library), Systems
- Dev mode runs fully without hardware (make dev)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

bordanlage/config/snapserver.conf

@@ -0,0 +1,16 @@
+[stream]
+source = pipe:///tmp/audio/spotify.pcm?name=Spotify&codec=pcm&sampleformat=44100:16:2&chunk_ms=20
+source = pipe:///tmp/audio/airplay.pcm?name=AirPlay&codec=pcm&sampleformat=44100:16:2&chunk_ms=20
+source = pipe:///tmp/audio/mopidy.pcm?name=Mopidy&codec=pcm&sampleformat=44100:16:2&chunk_ms=20
+
+[server]
+threads = -1
+
+[http]
+enabled = true
+bind_to_address = 0.0.0.0
+port = 1780
+
+[logging]
+sink = system
+filter = *:info