feat(kyberforge): enforce the ADR-0020 context contract for skills and agents

Skill name+description pairs are preloaded into every session, costing
~6,200 tokens across 39 skills before any skill is invoked. The authoring
rules mandated that growth: skill-author:104 and description-quality.md:21
both required padding, while skill-author:102 (the deflating rule) had no
FAIL condition behind it.

Gates (blocking, no baseline file):
- description 250 chars SUGGESTION / 400 FAIL, measured on the folded
  YAML value
- body-only 600 words SUGGESTION / 900 FAIL, independent of the unchanged
  whole-file 2770-word / 500-line spec backstop
- every boundary-clause routing target must resolve to a real skill or
  agent; catches skill-improve, neuledge-context and gitea-labels
- agents take the description gates but deliberately no body gate; a test
  pins that absence

Vale: DescriptionOpener widened to ^This\b, new CompositionNote rule
banning architecture notes from descriptions. 10 hits, 0 false positives.

Kyberforge's own four skills retrofitted: descriptions 3,364 -> 938 chars
(-72%), bodies 8,306 -> 2,487 words (-70%), all via the apm-workflow
dispatch pattern. Fixes the skill-improve dangling route and the
agent-author misroute to manual review.

Also fixes a pre-existing false positive where any line-initial 'read '
was flagged as interactive input, which had already caused two scripts to
be rewritten around it.

Refs: ADR-0020

LESSONS.md

@@ -177,3 +177,29 @@ Across one review round, four fixes specified by the orchestrating reviewer were
 Mutation testing a review round's own fixes found repeatedly that a passing test was pinning nothing. Deleting `sync_dir`'s stale-directory wipe, its check-mode stale branch, or three of five `MIRROR_DIRS` entries each left the suite at 18/18 green; so did replacing the hooks trailing-newline normalisation with plain `cp`. A pair of concurrency assertions written to guard a reentrancy defect caught it 0 times in 10 runs against the deliberately broken script — and one of them was structurally incapable of ever catching it, because the broken code wrote to the system temp dir while the assertion inspected `$TMPDIR`. A fixture-leak fix ran green with and without the fix, verified only by external observation. Two manifest fixtures passed with the canonicalisation they claimed to cover deleted, rescued by an unrelated name-matching axis. In each case the test named the right behaviour in its description and asserted something adjacent to it. The cheap discipline that finds all of these: for every assertion, construct the revert it is supposed to catch and confirm it fails — and when an assertion survives every revert you can think of, that is not reassurance, it is the finding (one test only revealed itself as decoration once a sixth, differently-targeted revert was built for it). Fix: treat "which revert does this fail against?" as a required answer at the time an assertion is written, and record it where the assertion lives, since a test's own description is exactly the artifact that made the gap invisible.
 
 Graduation candidate: this overlaps 2026-08-09's "an assertion written to cover an accepted residual tends to assert the residual's presence rather than the behaviour it costs" and the same date's "assert on the expected members, so a derivation whose input vanished fails loudly instead of quietly covering less." Three entries circling one pattern — human review for promotion to `core/instructions/testing.md`.
+
+## 2026-08-14 — Vale's `existence` extension concatenates `raw:` entries, it does not alternate them
+
+A new `Kyberforge.CompositionNote` rule was first written with seven `raw:` entries, one per banned
+phrasing. Vale loaded it without a diagnostic and it matched **zero of 43 files** — an outcome
+indistinguishable from a clean corpus, and the exact shape of 2026-08-08's "a clean linter result can
+mean nothing was checked". The cause is that `existence` joins multiple `raw:` entries into one
+pattern rather than OR-ing them, so the rule was searching for all seven phrases concatenated. Every
+pre-existing rule in this style has exactly one `raw:` entry, so nothing in the repo demonstrated the
+difference, and the multi-entry form looks natural beside them. `tokens:` is the alternated form,
+which is why `VagueWording` uses it. Fix: a new Vale rule is not landed until it has been shown to
+*fire* — the standing revert-check applies to linter rules as much as to tests, and the revert here
+is the broken multi-`raw:` form, which `tests/test-vale-hooks-consumer.sh` now fails against.
+
+## 2026-08-14 — Un-anchoring a description rule to reach mid-sentence text is unshippable
+
+Widening `DescriptionOpener` to catch `gitea-workflow`'s mid-description "This is the human-facing
+entry point…" looked like a one-character change. Under `scope: text.frontmatter.description`, `^`
+anchors to the start of the whole description value — and `vale-wrap.sh` has already flattened that
+value to one physical line, so `(?m)` changes nothing. Un-anchoring is therefore the only route to
+mid-description text, and measured across the corpus it scores 5 hits and 5 false positives: skills
+legitimately quote user phrasings (`says "audit this skill"`) and write boundary clauses (`do not use
+this skill to manage label definitions`). That is the `Kyberforge.VagueQualifier` deletion repeating.
+Fix: keep the opener rule opener-anchored and give mid-description prose its own rule with its own
+token list. A rule's scope anchor is part of its contract, not an implementation detail to relax when
+a new case does not fit.