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

docs/adr/0020-skill-description-and-body-context-contract.md

@@ -82,9 +82,11 @@ The body carries the **decision procedure only**: ordered steps, decision branch
 reference to load when. Lookup tables, spec restatements, output schemas, templates, and rationale
 prose move to `references/` behind an explicit "read X when Y" trigger.
 
-- **600 words SUGGESTION, 900 FAIL.** The 2,770-word / 500-line spec backstop is unchanged and keeps
-  its existing meaning: conformance, not quality. These are two different gates measuring two
-  different things, and conflating them is what produced the current state.
+- **600 words SUGGESTION, 900 FAIL, counted body-only** — everything after the closing `---` of the
+  frontmatter. The 2,770-word / 500-line spec backstop is unchanged, keeps its existing meaning
+  (conformance, not quality), and keeps counting the **whole file including frontmatter**. These are
+  two different gates measuring two different things, and conflating them is what produced the
+  current state.
 - **Dispatch is mandatory at two or more mutually exclusive flows.** The body carries the dispatch
   table and the gates that apply to every branch; each flow lives in its own self-contained
   `references/` file. This is `apm-workflow/SKILL.md:33-41` promoted from accident to rule.
@@ -149,8 +151,12 @@ Three pre-existing contradictions are fixed in the same change, because they are
 
 ## Consequences
 
-**Editing any non-compliant skill now requires retrofitting it first.** 30 of 39 descriptions exceed
-400 characters and 14 of 39 bodies exceed 900 words. With the gate hot and no baseline, a one-line
+**Editing any non-compliant skill now requires retrofitting it first.** At decision time, 30 of 39
+descriptions exceeded 400 characters and 13 of 39 bodies exceeded 900 words — the latter counted
+body-only, which is what the new gate measures; the pre-existing 2,770-word gate counts the whole
+file including frontmatter, and the two must not be conflated. The change that carries this ADR also
+retrofits kyberforge's own four author/audit skills, so the figures on landing are **26 and 9**.
+With the gate hot and no baseline, a one-line
 fix to `gitea-prs` cannot be committed until that skill meets the contract. This is deliberate — it
 guarantees convergence and avoids a half-state — but it means the retrofit is lazy and *mandatory*
 rather than deferred. The follow-up retrofit issue should be prioritised accordingly, and the risk it