* fix(skills): stop OS sidecars marking an untouched skill as modified
Package identity compared a live user directory against a tree read from a
clean checkout, so anything the OS deposited counted as drift. One Finder
visit writes .DS_Store, which sorts before SKILL.md and misaligns the
index-aligned snapshot comparison — the copy became 'unrecognized', was
reported as "may be modified... Remove it", and left out of the update.
Running the update could not clear it either: the updater compares its lock
to the source and never reads disk, so it correctly reports "up to date"
and writes nothing.
Ignore OS-authored names on both sides of the comparison. The generator
half is not hypothetical: a stray sidecar in a working tree made the
committed artifacts read as stale, failing lint for that developer.
Scoped to OS-authored names only. Tolerating unexpected files in general
would let an injected payload ride along beside a clean SKILL.md; these are
safe because an official SKILL.md never references them, so no agent can be
routed into one. Mode bits are deliberately untouched — that would weaken
identity for real scripts.
* fix(skills): keep guarding a directory or link wearing an OS metadata name
The name-only skip dropped any entry matching an OS metadata name, so a
directory named .DS_Store or ._scripts took its whole subtree out of
identity and a symlink wearing one stopped tripping the link guard — a
skill hiding either read as pristine. The OS writes these as plain files
only, so the entry type decides, still ahead of the case-fold map.
Also compares both walkers over the same fixture: an asymmetric skip is
worse than none, since one side would bake in content the other can
never observe.
* chore: ignore the OS metadata names skill identity already skips
Both skill-identity walkers ignore these names, but .gitignore covered only
.DS_Store and Thumbs.db — so a stray ._SKILL.md showed as untracked and
`git add -A` could commit it. That is the one way the two walkers can
disagree: the disk walker skips such a file while the git-tree producer
(collectGitPackageFiles, used by the unreferenced --rebuild-from-tags path)
does not, so a committed sidecar would make released history and observation
describe different content.
Ignoring them keeps that asymmetry unreachable rather than adding a second
skip to the released-history path, which is load-bearing and provably never
sees one today: no committed sidecar exists on any ref.
Nothing tracked matches the new patterns.
* chore: correct the skill-identity ignore comment
The previous wording claimed these names cannot be committed, which
overstates what .gitignore provides: `git add -f` and `git apply --index`
both bypass it, so a cherry-pick, rebase or fork branch already carrying a
sidecar is unaffected. That clause was load-bearing — it was the stated
reason for leaving the released-history producer unhardened — so it should
not read as a structural guarantee.
Also fixes the producer count (three, not two: two disk walkers plus the
git-tree producer, which does not skip) and says plain file, since the skip
is isFile()-gated so a directory or link wearing the name is still walked.
49cfbf014c