refactor(skills): retrofit the corpus to the ADR-0020 context contract (#129)

Retrofits all 39 skills to ADR-0020's description/body context contract, then fixes what six rounds of independent review found in that retrofit — including four ways the hot gate itself failed open.

Closes #99, #107, #108, #110, #111, #114, #115, #120.

## The retrofit (waves 1-5)

| | Start | Now |
|---|---|---|
| Description FAILs (>400 chars) | 26 | **0** |
| Body FAILs (>900 words, body-only) | 9 | **0** |
| Dangling routing targets | 2 | **0** |
| `Kyberforge.CompositionNote` | 10 | **0** |
| Preload tax | 21,005 chars | **~10,500** |

Under the 12,000-char success criterion. Per-wave detail is on #99.

## The review fixes

**The gate failed open four ways, three of them found after the retrofit shipped.** An unrecognised follower token made a dangling target vanish. A skill directory with no `SKILL.md` resolved as a valid target, so a commit could be green locally and red in a fresh clone — three existing fixtures were relying on that, one of which made the install-leak A/B pass vacuously. Then the free-standing `/name` sweep turned out to be gated on the sentence carrying a boundary marker, so route notation in any other sentence was invisible — not an ERROR, not a SUGGESTION, not an INFO — which left the documented "`/name` always blocks" promise false from a second direction. All four fixed and pinned.

**Two checks were silently not running.** `validate-provenance.sh` checks 7-8 were dead across nine skills. Waking them exposed a deeper problem: they assume `Research doc:` names a source index, but 30 of 121 entries point at topic content documents, so every new check-7 INFO was a false positive and check 8 was saved from a false-FAIL flood only by an *unannounced* skip. Checks 7/8 are now scoped to source indexes and every skip announces itself (#121).

**The retrofit's own anti-goal, four times.** ADR-0020 warns that a blunt gate gets satisfied by deleting content rather than relocating it. `diagnose` and `skill-audit` relocated prose and then read it unconditionally; `prototype` and `vale-config` deleted rules outright that survived nowhere. All four addressed.

## Verification

- `bash tests/run-tests.sh --strict` — 24 suites, 0 skipped, 0 failed
- `bash tests/run-bats.sh` — 325 tests, 0 failures
- `pre-commit run --all-files` — 17/17
- `pre-commit run --hook-stage pre-push --all-files` — 16/16, with `apm marketplace check` and `apm pack --check-clean` run against the remote, not skipped
- `scripts/skill-size-check.sh` over all 39 skills — rc 0, 0 ERROR/FAIL, SUGGESTION-only
- Preload tax measured at **10,498 chars**, max description 390 — both inside budget
- Every new test proven non-vacuous by a deliberate mutation of the behaviour it covers

**Per-commit sync, stated accurately:** the ten commits from the latest review round each pass `check-plugin-content-sync` in isolation, verified by checking each out in a detached worktree with a clean between. The earlier gitea window (`dfacf05..bedbd1d`, nine commits) does **not** — its mirror was regenerated in one batch at `bbc7300`. An earlier revision of this description claimed the property held for every commit; it does not, and a bisect through that window lands on a red commit. **Squash-merge** to collapse it, or accept that this range is not bisectable.

## Version bump

Six plugins and the catalog take a **patch**, not a minor. The branch is **89 commits — 40 `fix` / 30 `refactor` / 12 `docs` / 5 `chore` / 2 `test` — zero `feat`, zero `!`, zero `BREAKING CHANGE`** — and adds no skill, agent, command or hook. (Two earlier revisions of this section cited a stale histogram, most recently 78 commits; the figures above are measured at HEAD.) Both rules this repo ships (`forge/references/version-bump.md`, landing in this PR, and `git-commits/references/conventional-commits-spec.md`) make that a patch, and the catalog set is unchanged at 7 entries.

Not settled by that: four published files were removed from the installed tree, three moved, and `caveman` gained `disable-model-invocation`, retiring its old triggers. Under a strict reading those are major-class and currently ship under `refactor:` with no marker. Whether the deployed skill surface is a public contract is written down nowhere — worth deciding, but it outlives this PR.

## Deliberately not in scope

#112 (cherry-pick ownership, now resolved in favour of `git-commits`), #113 (`rtk git` normalisation), #116 (research fan-out), #101 (audit-skill merge), #122 (non-spec skill-root files), #123 (no PRD producer) stay open. #117 is the one worth reading: the contract's remedy is to move prose into `references/`, which is exactly where neither the size gate nor Vale looks — and the blind spot is wider than #117 currently records, since there is no root `.vale.ini` at all, so every ADR, `CONTEXT.md` and `README.md` is unlinted too.

That blind spot let this branch carry two `level: error` `Kyberforge.SentenceOpenerThereIs` violations into `references/` files it created — `provider-adapter-author/references/provider-matrix.md:31` and `agent-audit/references/finding-criteria.md:95`. Both are reworded in `afadaae`, confirmed by routing each file through the audit's own `vale-wrap.sh` (1 error each before, 0 after). Five further occurrences sit in `references/` files already on `main`; those are the pre-existing corpus and stay with #117, which is the real fix.

Also unfixed and not this PR's: `apm install` appends a duplicate `SessionStart` entry to `.claude/settings.json`, so a fresh clone cannot get pre-push green without an edit AGENTS.md warns against. Reproduces identically on `main`.

Co-authored-by: Defame1297 <gitea@rkdr.net>
Reviewed-on: https://git.dev.rkdr.net/Defame1297/holocron/pulls/129
Co-authored-by: Claude Code AI - Gitea MCP <claude@noreply.git.dev.rkdr.net>
Co-committed-by: Claude Code AI - Gitea MCP <claude@noreply.git.dev.rkdr.net>

AGENTS.md

@@ -36,7 +36,7 @@ Fall back to raw shell only when no skill covers it.
 - **Do not add repo-owned keys to `.claude/settings.json`.** apm treats it as its own deployed artifact and `apm audit --ci` replays the install and diffs, so anything apm would not have written is permanent drift that fails the `apm-audit-ci` pre-push hook. A hook you want here is authored in `plugins/<name>/.apm/hooks/` and deployed by apm, never hand-written into that file. The `SessionStart` entry already in it is exactly that: kyberforge authors it in `plugins/kyberforge/.apm/hooks/hooks.json` and apm merges it in, so it is apm's own output, it is what the replay expects, and it belongs in the commit — do not strip it (ADR-0019). Machine-specific settings go in the gitignored `.claude/settings.local.json`; shared enforcement goes in `.pre-commit-config.yaml`.
 - **`apm.lock.yaml` turning up modified is expected, not a bug.** kyberforge's `SessionStart` hook runs `apm outdated` at startup and `apm update --yes` when something is behind, which rewrites the lock. Commit or discard it deliberately.
 - **A `.apm/` edit is not live in this session until it is pushed.** The six dependencies resolve from the holocron remote, unpinned against the default branch. `apm install` deploys from the lock; `apm update` is what re-resolves refs.
-- **The ADR-0020 skill gates ship hot, with no baseline.** 26 of 39 descriptions and 9 of 39 bodies exceed their FAIL tier, and the `Kyberforge.CompositionNote` Vale rule fires 10 errors across `gitea-issues`, `gitea-labels-milestones`, `gitea-prs` and `gitea-workflow`. Editing any of those skills *for any reason* means retrofitting it to the contract first — a one-line fix cannot be committed until the skill complies. Deliberate; tracked as Gitea issue #99. `skill-size-check` will not warn you about the Vale half, so check both: `pre-commit run --all-files`.
+- **The ADR-0020 skill gates ship hot, with no baseline — and the corpus is now clean.** All 39 skills clear both FAIL tiers: no description over 400 characters, no body over 900 words (counted body-only). Retrofitted plugin by plugin under #99 (see `docs/spec/gates.md`). Because nothing is grandfathered, the gates now bite on first commit — a new skill, or an edit that pushes a description past 400, is blocked until it complies. **No routing target dangles**, and `tests/test-adr0020-targets.sh` pins that set as empty, so a new boundary clause naming a non-existent skill fails the suite rather than joining a backlog. Two blind spots survive: `skill-size-check` does not cover the Vale half, so `Kyberforge.CompositionNote` fires nowhere today but any new description can reintroduce it; and no `references/` file is linted by anything, so prose relocated out of a body to satisfy the word gate lands outside the prose gate. It has two independent causes and closing either alone changes nothing — `docs/spec/gates.md` has both, issue #117 tracks it. Check both gates: `pre-commit run --all-files`.
 - **Run `bash tests/run-tests.sh --strict` before considering any change done.** Keep the flag: without it a suite whose dependency is missing exits 77 and is counted SKIPPED rather than failed, so the run goes green having verified less than it claims.
 - **Before pushing, rehearse the gate locally:** `pre-commit run --hook-stage pre-push --all-files`. It runs the 14 pre-push hooks this repo authors itself plus pre-commit's 2 `meta` hooks, so it prints 16; `check-release-needed` passes without checking anything, because it needs a real push to `main`. `docs/spec/gates.md` reconciles both.
 - **Pushing without a network** needs `SKIP=apm-marketplace-check,apm-pack-check-clean git push` — those two resolve a remote marketplace entry via `git ls-remote`. Skip only those two; the rest are real local checks, and adding one to `SKIP` disarms it silently.