pv extract walks outside its input dir (parent of <dir>): 9.9 s release / 56 s debug vs 0.00 s #5780

Owner: flow (aprender-flow). Asked by aprender-57. Root defect behind #5779.

pv extract <dir> reads the filesystem OUTSIDE <dir>: it walks the parent of its input (strace: 2.2 M statx, 689 k getdents64, 350 k openat for a 3-file fixture; the paths were sibling directories under /tmp).

Evidence (same 3-file fixture, host, load ~8):

• parent = /tmp (19,631 entries, 60 G): 9.9 s old release pv, 56 s debug pv
• parent = an empty dir: 0.00 s
• an EMPTY input dir costs the same 9.9 s, so the cost is independent of the input.

Expected: extract reads only <dir> plus the paths its contracts name (entity.ref), and its time does not depend on what sits beside <dir>.
Candidate sites (not located, not measured): crates/aprender-contracts/src/ontology/extract/ apr_model.rs:171 (contract_dir.parent() as root), code.rs, binary.rs.
Falsifier: pv extract on a fixture dir under a parent holding 20 k entries runs in <1 s.
Test-side mitigation: branch work/5779 (nests the fixture); it does not fix pv.