write
suspend fun writeTileUserData(content: GpkgContent, zoomLevel: Int, tileColumn: Int, tileRow: Int, tileData: ByteArray): Long
Upsert the tile blob for (z, x, y) and return its tile-user-data row id (the tpudt_id that writeTileRevalidation keys freshness by). The id is stable across rewrites — the row is reused, not re-inserted.