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

plugins/kyberforge/.apm/skills/agent-author/assets/README.md

@@ -3,6 +3,7 @@
 ## templates/
 
 Annotated agent definition templates copied by `scripts/new-agent.sh` when scaffolding a new agent.
+All three scaffold the `description` in the three-part ADR-0020 shape — a `Use when` trigger clause, at most one capability clause, and a boundary clause — rather than the deleted action-verb opener, and each carries a delegate-don't-restate note in the body.
 
 - **`claude-code.md`** — Claude Code agent definition template (project/user scope). Includes all supported frontmatter fields (required and optional) with inline guidance comments and `FILL IN:` placeholders.
 - **`copilot.agent.md.template`** — Copilot CLI agent definition template (CLI format, project/user scope). Excludes cloud/IDE-only fields (`target`, `user-invocable`, `disable-model-invocation`, `mcp-servers`) and Claude Code-only fields. Uses Copilot tool aliases (`execute`, `read`, `edit`, `search`, `agent`, `web`).