feat: add deinterleave function and enhance graphics extraction for Slots and Card Flip

Implemented a new deinterleave function in ImageWriter to restore row-major order for PNGs. Updated RomExtractorGen2 to utilize this function for extracting Slot Machine graphics, and added new functions for padding and writing graphics sheets. Updated the ROM manifests to include necessary symbols for Slots and Card Flip assets.

src/import/ImageWriter.lua

@@ -125,6 +125,26 @@ function ImageWriter.columnsToRows(raw, tilesWide, tilesHigh, bytesPerTile)
   return out
 end
 
+-- Inverse of pret tools/gfx --interleave (pokecrystal tools/gfx.c).
+-- Build-time interleave stores each vertical 8x16 pair as consecutive 8x8
+-- tiles for OBJ mode; this restores row-major sheet order for PNGs.
+function ImageWriter.deinterleave(raw, width, bytesPerTile)
+  bytesPerTile = bytesPerTile or 16
+  local widthTiles = width / 8
+  local numTiles = #raw / bytesPerTile
+  local out = {}
+  for i = 0, numTiles - 1 do
+    local row = math.floor(i / widthTiles)
+    local src = i * 2 - (row % 2 == 1
+      and widthTiles * (row + 1) - 1
+      or widthTiles * row)
+    for offset = 1, bytesPerTile do
+      out[i * bytesPerTile + offset] = raw[src * bytesPerTile + offset]
+    end
+  end
+  return out
+end
+
 function ImageWriter.save(image, path)
   local ok, fileData = pcall(image.encode, image, "png")
   if not ok then error("could not encode " .. path .. ": " .. tostring(fileData)) end