Testing TileID 551 with different algorithms:

Current (Hilbert):
  TileID 551 → z=5, x=6, y=10

Simple ZXY order:
  TileID 551 → z=5, x=18, y=6
  Test: pmtiles tile raster.pmtiles 5 18 6

Testing first 20 TileIDs:
TileID | Simple Z/X/Y  | Test Command
-------|---------------|-------------
     0 |  0 /   0 /   0 | pmtiles tile raster.pmtiles 0 0 0
     2 |  1 /   1 /   0 | pmtiles tile raster.pmtiles 1 1 0
    10 |  2 /   1 /   1 | pmtiles tile raster.pmtiles 2 1 1
    36 |  3 /   7 /   1 | pmtiles tile raster.pmtiles 3 7 1
   140 |  4 /   7 /   3 | pmtiles tile raster.pmtiles 4 7 3
   551 |  5 /  18 /   6 | pmtiles tile raster.pmtiles 5 18 6
   553 |  5 /  20 /   6 | pmtiles tile raster.pmtiles 5 20 6
  2195 |  6 /  62 /  12 | pmtiles tile raster.pmtiles 6 62 12
  2197 |  6 /   0 /  13 | pmtiles tile raster.pmtiles 6 0 13
  2199 |  6 /   2 /  13 | pmtiles tile raster.pmtiles 6 2 13
  2202 |  6 /   5 /  13 | pmtiles tile raster.pmtiles 6 5 13
  8764 |  7 / 103 /  25 | pmtiles tile raster.pmtiles 7 103 25
  8768 |  7 / 107 /  25 | pmtiles tile raster.pmtiles 7 107 25
  8770 |  7 / 109 /  25 | pmtiles tile raster.pmtiles 7 109 25
  8772 |  7 / 111 /  25 | pmtiles tile raster.pmtiles 7 111 25
  8774 |  7 / 113 /  25 | pmtiles tile raster.pmtiles 7 113 25
  8776 |  7 / 115 /  25 | pmtiles tile raster.pmtiles 7 115 25
  8778 |  7 / 117 /  25 | pmtiles tile raster.pmtiles 7 117 25
  8782 |  7 / 121 /  25 | pmtiles tile raster.pmtiles 7 121 25
  8789 |  7 /   0 /  26 | pmtiles tile raster.pmtiles 7 0 26

Test these commands and see if the tiles exist!
If they do, we need to switch from Hilbert to simple ZXY order.