refactor(kyberforge)!: merge skill-audit and agent-audit into factory-audit

Why

The two audit skills carried 1,724 lines of byte-identical duplication: the ADR-0020 boundary
resolver (1,061), vale-wrap.sh (526), the Vale style rules (44) and the Contributing-files parser
(93). Nothing shared them — they were held in sync by a 413-line pre-push gate and its 797-line
test suite. Sync-by-gate had already failed once: at 484357a the two parser copies drifted into
different spellings of the bullet loop while a docstring asserted they were identical. That drift
was behaviour-neutral and was re-unified by hand at 598a7c3, so the copies were identical at merge
time — but nothing had caught it, and the next drift need not be neutral.

Implementation Notes

Self-containment binds BETWEEN skills, not within one. The agentskills.io spec forbids reaching
across skill directories, which is why two separate skills needed embedded copies; two files inside
ONE skill may source a third. That is the whole reason the merge removes duplication rather than
relocating it.

The union of both bodies measured 1,532 words against BODY_MAX_WORDS=900, and only 211 of those
words were shared, so SKILL.md is a dispatch body. Step 0 resolves the flow from the target path
before any validation, and its table mirrors validate.sh's detection exactly: a directory holding
SKILL.md or a SKILL.md file (skill); a *.agent.md, or a .md directly under an agents/ directory
(agent); anything else stops without running a validator. Steps 1-3 live in
references/skill-flow.md and references/agent-flow.md, and gotchas that apply to one flow live in
that flow's file, since it is loaded on every invocation anyway. If validate.sh reports on the
other artifact type, the body restarts at Step 0.

Named factory-audit rather than forge-audit because forge is a live skill, and a family prefix that
matches a live sibling reads as ownership rather than membership.

The description carries one arrow per boundary target, because ADR-0020 resolves only the first
target after an arrow. It drops the quoted "audit this skill"-style phrases, which restated
"audited" in a second register (ADR-0020's duplicate-register rule). 241 characters, Gotchas 16%
of the body: no size SUGGESTIONs.

The boundary resolver stays embedded in two files rather than imported: a cache-installed plugin
cannot read outside its own directory, and the repo-root hook resolves via .pre-commit-hooks.yaml
where entry[0] is the only token pre-commit rewrites, so no single file is reachable by both.
tests/test-adr0020-contract.sh hashes both copies for byte-identity, and asserts validate.sh sources
the resolver and that no third copy exists.

The entry scripts classify the target from its resolved parent directory, so a bare agent filename
typed inside agents/ works; resolve SCRIPT_DIR CDPATH-safely; and exit 2 when a lib-*.sh is
missing, rather than dying with exit 1, the tier the flows relay as real findings.

The provenance run functions stash their findings code in KYBERFORGE_PROV_RC and
return 0, so validate-provenance.sh calls them UNTESTED. Testing a function's
status (`f || RC=$?`) disables errexit for its entire body, and no subshell or
`set -e` inside can re-arm it once the call sits in a condition context
(measured, both spellings). Their error paths use `exit`, which is unaffected
either way; this keeps errexit armed for anything added later.

Case 0's readability guard reads the file instead of asking `[[ -r ]]`. `-r` is
access(2), which answers yes for uid 0 even on a mode-000 file, and this repo's
dev environment is root -- so the guard could never fire where it exists to fire.
A read attempt is also the stricter question, catching EIO. This is the reasoning
scripts/check-vale-style-sync.sh carried before this commit deleted it; the
hazard did not go with it.

All three entry scripts are CDPATH-safe, vale-wrap.sh included: both of its cd sites are cleared,
the --config resolution and the directory-mirror walk, where an exported CDPATH would otherwise
print a decoy path into the -print0 stream and build the mirror from the decoy's files. The two
remaining bare cd calls take absolute paths, which CDPATH is never consulted for.

Impact

BREAKING: skill-audit and agent-audit no longer exist as invocable skills. kyberforge goes to
2.0.0 (catalog 0.4.7).

Check logic is unchanged: differential runs of the old and new validators across every skill and
agent produced byte-identical stdout, stderr and exit codes, and the reconstructed Python payloads
differ only in comments and the references/field-inventory.md -> agent-field-inventory.md rename.
One doctrine governs the tiers: exit 0 is audited and clean, exit 1 is audited with findings OR a
target present but unreadable, exit 2 is that nothing was audited at all. Edge paths DID change,
deliberately (full table in ADR-0025):
- a missing target exits 2 (never ran), not 1, under its own "does not exist" message; detection is
  by path shape, so a shape-matching path that is simply absent used to reach the validator and come
  back as a FAIL against a file that never existed;
- an unshaped target exits 2 under the generic "matches neither" message, and a directory with no
  SKILL.md under a third, distinct one -- three exit-2 messages, not one;
- a dangling symlink or a symlink loop stays exit 1: it is present but broken, which is a finding
  about the artifact rather than a usage error;
- a SKILL.md file path is audited as its skill directory instead of refused;
- a .md agent outside an agents/ directory is refused rather than audited;
- a missing script library, a missing python3, a missing PyYAML, and no argument at all each exit 2.
  validate-provenance.sh already exited 2 for the last two; validate.sh now matches it.

.pre-commit-hooks.yaml is a published contract consumed by external repos. Both hook IDs and both
files: regexes are unchanged; only entry: and description: moved.

scripts/check-vale-style-sync.sh (413), scripts/sync-vale-styles.sh (21),
tests/test-check-vale-style-sync.sh (797) and agent-audit/scripts/README.md (47) are deleted. The
checker made 17 assertions: 6 compared the two Vale copies and are moot; 10 are rehomed into
tests/test-vale-wrap.sh (case 0, cases 28-31, and the suite's Vale-absent skip); and the
cross-manifest files: agreement check, which selected hooks by entry: and so could not survive both
hooks sharing one, is ported as case 33 pairing hooks by id:. Cases 28, 30 and 33 carry mutation
self-tests; narrowing the local skill prefilter to 6 of 38 SKILL.md files now fails the suite.

Skills go 39 to 38. Pre-push goes 9 repo-authored hooks to 8.

ADR: 0025
BREAKING-CHANGE: the skill-audit and agent-audit skills are removed. Both flows are served by
  factory-audit, which auto-detects whether it was handed a skill directory or an agent file.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YR2CjVumUbEGWcMikcoXBD

plugins/kyberforge/.apm/skills/factory-audit/references/skill-file-structure.md

@@ -0,0 +1,72 @@
+---
+source_keys:
+  - agentskills-spec
+---
+
+# File Structure and Internal Consistency Reference
+
+Upstream source: agentskills.io — specification (optional directories, file references).
+
+Read this when judging the **file-structure** and **internal-consistency** dimensions.
+
+## Permitted directories
+
+Only four: `scripts/`, `references/`, `assets/`, `tests/`. The specification permits additional
+directories; this house does not, because an unlisted directory is content no auditor and no host
+knows to look at. Flag any other directory as a FAIL.
+
+- `scripts/` holds only executable code an agent can run, and the sourced libraries those entry
+  points load. A `lib-*.sh` that is never invoked on its own belongs here beside the entry point
+  that sources it — it is executable code, not documentation, so do not flag it for failing to run
+  standalone. Test files (`.bats`, `*_test.*`, `test_*.sh`) there are a FAIL — they belong in
+  `tests/`.
+- No non-spec files at the skill root: no `META.md`, no stray config outside the four directories.
+- An optional directory that exists must hold real content, not an unfilled placeholder README.
+
+## Cross-plugin path references
+
+A plugin is copied to a cache on install, and a path that climbs out of the skill directory stops
+resolving there. Flag a path in `SKILL.md`, `scripts/`, `references/` or `assets/` when it
+**resolves outside the skill directory** — an absolute repo path
+(`plugins/<plugin>/skills/<other>/` and its APM-native equivalent `.apm/skills/<other>/`), a
+plugin-root path (`docs/`, `bin/`), or a `../` chain that leaves the skill root.
+
+Resolve before flagging, twice over:
+
+- **Resolve the path.** `$SKILL_DIR/../assets/templates` climbs one level from a `scripts/`
+  directory and lands back inside the same skill, so it resolves in a cache install and is not a
+  finding. A bare `../` is not the defect; leaving the skill is.
+- **Skip fenced code blocks.** A path inside a fenced block is an example, and rubrics quote outside
+  paths deliberately as negative examples of what not to write. Flag a fenced path only when the
+  surrounding prose presents it as the form to copy.
+
+**Referring to another skill's file.** There is one sanctioned spelling, and it is possessive:
+`skill-author's references/contract.md`. Write the skill by name and let the reader
+resolve it — do not spell the repo path. The full path is the thing this section forbids, and
+`references/contract.md` on its own is a hard ERROR from the gate, which
+requires an unqualified `references/` pointer to exist in the skill's OWN directory. The
+possessive form is the only spelling both rules accept; the gate recognises it and skips the
+on-disk check. Flag any other spelling of a cross-skill reference.
+
+Two directories are exempt, and the exemptions are structural rather than discretionary:
+
+- **`references/sources.md`.** Its `Research doc:` fields are development-time provenance pointers,
+  not runtime references. They are expected to be unresolvable after install, so
+  `validate-provenance.sh` does not treat an absent path as a FAIL — it emits an INFO naming the
+  slug and stating that checks 7 and 8 did not run for it. Flagging them as broken references
+  would make every correctly-provenanced skill fail.
+- **`tests/`.** Test files are dev-only and may reference repo-level infrastructure such as a shared
+  `tests/test_helper/`. The exemption is conditional on the dependency being declared: if `tests/`
+  exists and `tests/README.md` is absent or does not document it, that is a FAIL.
+
+## Internal consistency
+
+The skill has to agree with itself. Two checks:
+
+- `SKILL.md`'s steps match what the scripts actually do — the arguments, the exit codes, and the
+  output shape it tells the agent to expect.
+- Placeholder READMEs inside `scripts/`, `tests/` and `assets/` say the same thing about each
+  directory that `SKILL.md` does.
+
+The FAIL and SUGGESTION criteria for this dimension live in `references/skill-finding-criteria.md`,
+which Step 3 loads on every run.