Stiger challenge - three levels, one public spec.

Statement, hints and flag hashes: https://onegoodman.studio/stiger/challenge
Spec and reference decoders:      https://github.com/axlerk/stiger-protocol
En espanol: LEEME.md

level1.png         open mode
level2.png         stealth-v3, the password is a 4-digit PIN
level3/sticker-*   eight stickers, three of them carry something (version 2,
                   14 October 2026: built the way Stiger now sends every
                   sticker, with a random blue low-bit plane on all eight)
level3-v1/         the first version of level 3, kept for the record: it fell
                   to a chi-square test on the blue low bits
