[AsYlum-]

• Transparent spots in game: background removal compared colors after reducing them to 5 bits per channel, so 248–255 white (and 168–175 grey in CV5/KR) became transparent. Now matched on the exact source color.
• Empty frames: Add / All directions add imported GIFs as empty frames, and only their first frame.
• Palettes: built from every frame of an import, colors outside the palette map to the closest entry instead of index 0 (black pixels), and existing frames are no longer recolored.
• Bmp/Jpg export: frames are saved on white instead of black, so they re-import cleanly.
• All directions add: also takes an action's exported images (..._{direction}_{frame}) and replaces its frames, keeping each frame's center.

Closes #45
Closes #28