--generate-variable-depth-tile-pyramid decides a tile is a leaf once its
geometry fits at full detail, then prunes the tile's entire subtree. The
guard that prevents leafing while deeper content is still pending consults
only feature_minzoom (the automatic dot-dropping zoom); it does not consult
tippecanoe_minzoom, the explicit per-feature minzoom set via the
tippecanoe.minzoom attribute.
So a feature carrying an explicit minzoom deeper than where its region leafs
is excluded from the leaf tile (z < minzoom) while its children are never
generated. It ends up in no tile at any zoom, silently dropped.
next_feature() excludes such a feature and continues without returning it,
so the leaf-prevention guard in write_tile() never sees it. Carry a flag out
of next_feature() when an excluded feature first appears beyond the next
zoom, and feed it into the same estimated-complexity path feature_minzoom
already uses, so the pyramid keeps subdividing down to the feature's minzoom.
The flag only affects estimated_complexity_out, which is written solely under
--generate-variable-depth-tile-pyramid, so builds without that flag are
unchanged. make test passes with no fixture diffs.
