Mix tasks don't run in production, so the orchestration lives in
Microwaveprop.Buildings.BulkFetch — callable from an attached iex on
the prod pod via:
iex> Microwaveprop.Buildings.BulkFetch.run(32.8, -97.0, 500)
Default 500 mi radius around DFW yields ~440 candidate quadkeys at
zoom 9; only those present in the MS dataset index (typically a few
hundred over CONUS) get downloaded. Concurrency 4, per-task timeout
3 min, results logged with downloaded/cached/failed/missing counts.
The mix.task is kept as a dev-only thin wrapper.
Phase 1 of building-blockage support: implements quadkey math (Bing/MS
tile encoding), looks up the MS dataset-links index for UnitedStates,
and downloads csv.gz quadkey tiles to /data/buildings (overridable via
:buildings_cache_dir). Index is cached 24h; tiles are written once and
reused. No path-analysis wiring yet — that's the next slice.
