Add offline map tile prefetch tooling

.gitignore

@@ -1,5 +1,9 @@
 .pio/
 .vscode/
 *.pyc
+/tiles/
+prefetch_map_tiles.stderr.log
+prefetch_map_tiles.stdout.log
 docs/flasher/firmware/
 lib/tdeck_ui/Hardware/TDeck/SplashImage.h
+deps/microReticulum

tools/README.md

@@ -0,0 +1,65 @@
+# Map tile prefetch script
+
+`prefetch_map_tiles.py` downloads raster XYZ map tiles in the same layout Pyxis expects on the SD card:
+
+```text
+tiles/{z}/{x}/{y}.png
+```
+
+## How it works
+
+- Uses a center point and radius in kilometers.
+- Computes all map tiles that intersect that area for the selected zoom range.
+- Downloads each tile as a PNG.
+- Saves the files into the Pyxis-compatible `tiles/` folder structure.
+
+## Tile provider requirement
+
+You must provide a tile URL template for a provider that explicitly permits bulk and offline downloads.
+
+Do not use `tile.openstreetmap.org` for this script. OpenStreetMap's public tile service prohibits bulk downloading and offline prefetching under the [OSM Tile Usage Policy](https://operations.osmfoundation.org/policies/tiles/).
+
+Use one of these instead:
+
+- a self-hosted tile server
+- a commercial provider and plan that explicitly allows offline or bulk prefetching
+
+The default center point comes from the coordinates shown in the provided screenshot:
+
+- latitude: `43.978093`
+- longitude: `-66.143359`
+- radius: `200 km`
+
+## Basic usage
+
+Dry run:
+
+```bash
+python tools/prefetch_map_tiles.py --dry-run
+```
+
+Download tiles:
+
+```bash
+python tools/prefetch_map_tiles.py --url-template "https://tiles.example.com/{z}/{x}/{y}.png" --min-zoom 8 --max-zoom 14
+```
+
+Custom area:
+
+```bash
+python tools/prefetch_map_tiles.py --url-template "https://tiles.example.com/{z}/{x}/{y}.png" --lat 44.0 --lon -66.1 --radius-km 100 --min-zoom 10 --max-zoom 15
+```
+
+## Copy to SD card
+
+After the download finishes, copy the generated `tiles/` directory to the SD card root so Pyxis can load files like:
+
+```text
+S:tiles/14/4823/6160.png
+```
+
+## Notes
+
+- Existing files are skipped unless `--overwrite` is used.
+- `--url-template` is required for actual downloads.
+- Bounding boxes that cross the antimeridian are split into two tile ranges so dateline-adjacent areas work correctly.