docs: amend ADR-0020 and correct the gate reference to match what ships

The ADR said a /slash target behind a route verb takes the follower test; the
implementation decides notation first and skips it. Recorded as a dated amendment
rather than a silent edit, per the ADR-0016/0017 convention.

Its Enforcement table called itself exhaustive 'because the failure this ADR is
most exposed to is a rule filed under Enforcement that no validator implements'.
Three shipped behaviours were missing, including the disable-model-invocation
carve-out that removes two rows. Also de-pins the 'zoom-out is the one carrier'
claim, which caveman falsified, and the stale dangling-target statuses.

gates.md's ERROR row made terminality a conjunct for route notation, telling an
author a form is safe that exits 1. It now documents the references/ Vale blind
spot and its two independent causes -- AGENTS.md trimmed to the operative rule
per the split gates.md itself states -- plus the undocumented skill-frontmatter
hook and the second scope exclusion. CONTEXT.md glosses 'routing target'.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EJJrm5YmacbwMdzZpXcoti

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 - **`apm.lock.yaml` turning up modified is expected, not a bug.** kyberforge's `SessionStart` hook runs `apm outdated` at startup and `apm update --yes` when something is behind, which rewrites the lock.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 — 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 every `references/` file is unlinted — which matters because the contract's own remedy is to move prose *into* `references/`, out of the prose gate's reach. That blind spot has **two** independent causes and closing either alone changes nothing: the `Kyberforge` style is scoped `[**/SKILL.md]` (the cause #117 records), *and* the `vale-audit-prefilter-skill` hook filters on `files: '^plugins/[^/]+/\.apm/skills/[^/]+/SKILL\.md$'`, so a reference file is never handed to Vale whatever the style says. Check both gates: `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.