Extend generated tiles through zoom 17

README.md

@@ -62,7 +62,7 @@ Input files are never modified or removed. Per-file errors are recorded in `tile
 
 The automatic maximum zoom for each overlay is calculated from the highest reprojected resolution in metres per pixel. The builder selects the highest tile zoom whose resolution is no more detailed than the source, avoiding pixel upscaling.
 
-The automatic minimum zoom is `0`: broad levels are inexpensive and make isolated maps discoverable from a world view. Each source stops at its native maximum, avoiding server-side pixel upscaling. To allow extra visual zoom, configure MapLibre with a high `maxZoom` and retain the source's native `maxzoom`; MapLibre will enlarge the last available tile. If no source covers the coordinate, the server uses the configured callback or white `empty.png`.
+The automatic minimum zoom is `0`: broad levels are inexpensive and make isolated maps discoverable from a world view. This repository sets global `maxzoom` to `17`, deliberately allowing enlargement above the native resolution so a map does not disappear into the callback while zooming. Set it back to `null` to keep the automatic per-overlay maximum. If no source covers the coordinate, the server uses the configured callback or white `empty.png`.
 
 `config/maps.json` supports global and source-relative overrides:
 

config/maps.json

@@ -1,7 +1,7 @@
 {
   "global": {
     "minzoom": null,
-    "maxzoom": null
+    "maxzoom": 17
   },
   "sources": {
     "Altis.kmz": {