The tree decompression budget was only spent as entry content was stored. A compressed tar reader
still decompresses whatever an entry leaves unread to reach the next header, so an excluded entry, a
file/directory clash, or the rest of one over the 2 GB per-entry cap decompressed with nothing charged
and no ctx check. A small `.tar.zst` could force hundreds of GB of work past the budget.
- in compressed tars the rest of every regular entry is now drained through the budget, with ctx
checked per chunk
- zip and plain tar are unchanged: they seek past skipped entries, so those cost nothing
Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>