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/skill-author/references/improve.md

@@ -0,0 +1,82 @@
+---
+source_keys:
+  - agentskills-best-practices
+  - agentskills-evaluating-skills
+  - agentskills-optimizing-descriptions
+---
+
+# Improving an existing skill
+
+Return to `SKILL.md` Step 4 once Step 4 below is done — validation, versioning and commit
+verification are shared with the create flow and are not repeated here.
+
+## Step 1 — Verify inputs
+
+Confirm the skill directory path exists and that at least one improvement signal is present in the
+conversation or a referenced file.
+
+If the skill directory is missing, ask for it. If no signals are present, stop: "This skill applies
+existing signals to a skill. For a blind review without signals, use `/skill-audit` instead."
+
+Signals can come from anywhere in the conversation or referenced files:
+
+- Grill session output (most common predecessor in the factory sequence)
+- `/skill-audit` findings (PASS/FAIL/SUGGESTION punch list)
+- Human feedback (feedback.json, inline in conversation, PR or issue comments)
+- Session context describing what went wrong
+
+Also verify the `name` field in frontmatter matches the skill's directory name exactly.
+
+## Step 2 — Gather and group signals
+
+Read the current skill files (SKILL.md and any files in `scripts/`, `references/`, `assets/`,
+`tests/`). Then collect all signals from the conversation and any file paths the user has
+referenced.
+
+Group signals by **root cause**, not symptom. Patching per symptom is the default failure mode:
+three eval failures may all trace to one missing instruction. Ask: "What single gap in the skill
+causes this cluster of failures?" One root cause → one fix. Do not make a separate edit for each
+symptom.
+
+```text
+Example:
+- Session context: output format is wrong on every run
+- Audit finding: no output template defined
+- User feedback: "I always have to ask it to format the output"
+→ Root cause: SKILL.md has no output format specification → one fix: add an output template
+```
+
+## Step 3 — Announce planned changes
+
+Before editing, state:
+
+- Which root causes were identified and what evidence supports each
+- Which files will be changed and what will change in each
+
+Then proceed — edits are reversible via git, no approval checkpoint needed.
+
+## Step 4 — Apply changes
+
+Edit any file in the skill directory that the signals point to: SKILL.md, `scripts/`,
+`references/`, `assets/`, `tests/`, README.md.
+
+**Generalize, do not patch.** Find the underlying gap, not the specific example that failed. A fix
+scoped only to the test cases you have seen will overfit and perform worse on new inputs.
+
+**Keep it lean.** Remove instructions that are not pulling their weight. For every sentence you
+add, ask: "Would the agent get this wrong without it?" A shorter, focused skill consistently
+outperforms an exhaustive one.
+
+**Explain the why.** Reasoning-based instructions outperform rigid directives. If you find yourself
+writing a rule in all caps (ALWAYS/NEVER), reframe it: explain why the behavior matters so the
+agent can apply judgment in edge cases.
+
+**Retrofit before extending.** Any edit to a skill that predates ADR-0020 has to bring it into the
+contract first — the gates are hot and carry no baseline file, so a one-line fix to a
+non-compliant skill cannot be committed until the description and body meet
+`references/contract.md`. Treat that retrofit as part of the same change, not a follow-up.
+
+If a signal points to a script or reference file, edit that file directly rather than adding a
+workaround in SKILL.md.
+
+Then return to `SKILL.md` Step 4.