Replace Leaflet + OSM raster tiles with MapLibre GL JS + PMTiles:
- Full continental US vector tiles (8GB PMTiles, zoom 0-14 with overzoom)
- Dark theme via @protomaps/basemaps (official supported path)
- Clustered device markers with status colors (green/yellow/red)
- Popup cards show CPU, memory, wireless client count + avg signal
- Font glyphs proxied through nginx, sprites served locally
- Zero third-party requests from the browser
- Fleet summary SQL now includes wireless client count and avg signal
via LEFT JOIN LATERAL on wireless_links
Also removes alert toast spam and fixes map container height.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
