0a0a0333dd
A wave runs to data_at + declared_size, and there is seek magic exactly there whose little-endian packet count at +12 times 2048 equals the declared size -- 7620/7620 disc-wide. That is the decoder-independent boundary and the thing that proves the declared sizes honest, so it should not be able to regress silently. The boundary routinely lies outside the entry's own comp_size window, so reading it needs the flat segment stream rather than the entry slice; PakArchive gains a small data_at(offset, len) accessor for that. Test walks a bounded slice to stay fast -- 792 banks in this run, all holding. 8 disc tests pass.