Adds a per-cell building-clutter penalty so the algorithm down-ranks
spots in built environments where buildings on multiple sides
scatter/block signal regardless of which station you're aiming at.
Penalty = max_height_within_75m / 5 dB, capped at 6 dB. Path-clearance
already accounts for buildings ON the link path; this is the
"surrounded by stuff" signal.
- Local prominence: each cell's elevation vs. its 8-neighbor ring
(~1.3 km radius) feeds a small additive bonus so broad hilltops
rank above isolated SRTM voxels
- Road proximity: one Overpass call per Calculate fetches drivable
ways inside the bbox; cells beyond ~0.5 km of any road get a
light dB penalty, gated off in tests
For each (rover cell, fixed station) pair, sample SRTM along the
great-circle path and add a per-link dB bonus proportional to the
rover's elevation above the highest intermediate terrain. Rover spots
on hilltops with clear sight to multiple stations now rise to the top.
Also vendor Leaflet's layers control PNGs and copy them under
priv/static/assets/css/images/ on build so /rover stops 404'ing on
layers-2x.png.
