fix(kyberforge): correct the routing-tier contract and make agent-audit rubrics conditional

Five documents told authors that a prose-form dangling routing target blocks. The
gate reports it as a SUGGESTION and exits 0. Verified on fixtures: `-> name` and
`/name` are blocking ERRORs, the prose form is SUGGESTION-tier unless a second
resolving target in the same sentence corroborates it. ADR-0020 and gates.md were
right; contract.md, retrofit.md, description-quality.md, finding-criteria.md and
agent-author's contract.md were wrong — and they are what an author and an auditor
actually read. The whole 39-skill corpus was retrofitted against them.

skill-audit was also self-contradictory: it imports validate.sh's SUGGESTIONs into
the Structure dimension verbatim while its own rubric grades the same target a FAIL,
so one target got reported twice at two tiers. The script owns the grade; the rubric
now says so.

The YAML-fold trap that broke gitea-labels-milestones (#100) was warned about only
in retrofit.md, reachable only from the improve flow when a budget is exceeded. It
is now in both contract.md files, which SKILL.md mandates on the create flow too.

agent-audit loaded both rubrics unconditionally on every run — 3,323 words for a
clean audit against skill-audit's 1,636. dac9cad fixed exactly this in skill-audit
and edited agent-audit in the same commit without applying it. Same treatment: the
criteria move to a new finding-criteria.md and load per dimension. Clean run now
2,083 words, a 37% cut.

Routing: apm-workflow's description shed dependency installation while still owning
the flow, and apm-install's boundary did not exclude it, so "install my apm
dependencies" matched the CLI-binary skill with no route back. Fixed on both sides.
forge regains two of the three phrasings the retrofit deleted.

forge Step 1 called grill-with-docs unconditionally — a skill in plugins/bin, which
kyberforge does not declare as a dependency. It resolves here only because the
walk-up sweeps sibling plugins; a standalone install dead-ends. Step 1 now names
the cross-plugin dependency and gives an inline fallback. Declaring it properly in
apm.yml remains the better fix.

Also: both audit SKILL.md files now grade exit 2 as "did not run, dimension
unverified" rather than as findings; skill-audit's README row described content that
moved, which its own finding-criteria.md grades a FAIL; and body-discipline.md's
`git show <sha>:plugins/...` command is fenced, since an installed plugin cache has
no repo and file-structure.md makes a bare repo path a FAIL.

Refs: #100, #101, #125
ADR: 0020

plugins/kyberforge/skills/skill-audit/SKILL.md

@@ -33,11 +33,11 @@ bash scripts/validate-provenance.sh <skill-dir>
 bash scripts/vale-wrap.sh <skill-dir>/SKILL.md
 ```
 
-`validate.sh` findings become the `### Structure` dimension — its FAILs and its SUGGESTIONs both.
+`validate.sh` findings become the `### Structure` dimension — its FAILs and its SUGGESTIONs both, at the tier the script assigned. Report each once; never re-grade one under another dimension. Unresolved boundary targets are where this bites, because their tier turns on notation.
 
 If any of the three cannot run, or exits non-zero for a reason other than findings, read `references/validation-scripts.md` — it carries the manual fallback and the misleading exit codes. Ordinary content FAILs are the expected outcome here and need no fallback.
 
-`validate-provenance.sh` prints nothing on success. Its FAIL and INFO findings become a separate `### Provenance` dimension, and it emits Why and Fix itself — surface those verbatim.
+`validate-provenance.sh` prints nothing on success, so read its exit code before you read its silence. **0** is a genuine pass. **1** means real findings: its FAILs and INFOs become a separate `### Provenance` dimension, and it emits Why and Fix itself — surface those verbatim. **2** means the check never ran — a usage or environment error, reason on stderr, no findings and often no stdout at all. On a 2, report `### Provenance` as unverified and quote the stderr reason. Never grade an exit 2 as a clean pass: empty stdout there means nothing was checked, not that nothing was wrong.
 
 `vale-wrap.sh` applies the bundled `Kyberforge` style as a prefilter. Pass no `--config`; the wrapper locates its own. Every rule is graded `error`, so every alert is a FAIL. Report each one citing its rule ID, filed under the dimension it belongs to, and do not re-derive it by judgment: