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/nginx/default.conf

@@ -0,0 +1,48 @@
+server {
+    listen 80;
+    server_name _;
+    root /usr/share/nginx/html;
+    index index.html;
+
+    # Serve React app – HTML5 history mode
+    location / {
+        try_files $uri $uri/ /index.html;
+    }
+
+    # Proxy SignalK
+    location /signalk/ {
+        proxy_pass http://signalk:3000/signalk/;
+        proxy_http_version 1.1;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection "upgrade";
+        proxy_set_header Host $host;
+    }
+
+    # Proxy Snapcast WebSocket API
+    location /snapcast/ {
+        proxy_pass http://snapserver:1780/;
+        proxy_http_version 1.1;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection "upgrade";
+        proxy_set_header Host $host;
+    }
+
+    # Proxy Mopidy
+    location /mopidy/ {
+        proxy_pass http://mopidy:6680/mopidy/;
+        proxy_http_version 1.1;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection "upgrade";
+        proxy_set_header Host $host;
+    }
+
+    # Proxy Jellyfin
+    location /jellyfin/ {
+        proxy_pass http://jellyfin:8096/;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+    }
+
+    gzip on;
+    gzip_types text/plain text/css application/json application/javascript;
+}