main.swift: servePackProgram reads program.h with the packfile.h checks (generator 2 or 3, the class line against
the generator, the seed bytes, IGNEUM_SEEDW_INIT against attempt_words, class and era against the line) and
compiles program_bound.metal; the program store keys on (seed, class, era); a v3 job with no resident v3 pack
program answers need + error; v2 lines unchanged (Swift generation, the variant race); a pack program never races.
verify.rs: Epoch::chain_dataset_day(day, class, days_since_genesis, genesis_dataset_log2) and days_since_genesis,
the entry the node builds every day cache through (the ca2-mixer growth rule fills the body).
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>