A single `!` rule in .graphifyignore set a blanket `has_negation` flag that
disabled directory-level pruning for EVERY ignored directory during the
os.walk in detect(). One unrelated `!docs/**` therefore made the walk descend
bin/, obj/, wwwroot/, generated/, … on large repos — a pathological slowdown.
Output stayed correct (the per-file `_is_ignored` filter still excluded those
files), but the walk visited the entire tree.
The bypass was unnecessary: `_is_ignored` already honours negations correctly —
last-match-wins lets `!dir/` un-ignore a directory (so it is not pruned), and
the gitignore parent-exclusion rule means a `!` cannot rescue a file beneath an
excluded directory, so descending an ignored dir to find a re-included file is
never needed. Prune purely on `_is_noise_dir` + `_is_ignored`.
Adds a regression test that tracks os.walk and asserts the ignored dir is never
descended while the negation still re-includes its target.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
