MvtSchemaDetector

Identifies which vector-tile schema a decoded MvtTile follows by inspecting its layer names. Useful for auto-selecting a compatible style — feeding an OpenMapTiles tile to a Shortbread style (or vice versa) produces a mostly-empty map because almost no layer names line up.

Detection is best-effort: the schemas overlap on some generic names (buildings), so we key off the schema-specific signature layers. A tile that matches multiple signatures counts toward the schema with the largest match; ties resolve toward Schema.UNKNOWN.