fix(kyberforge): apply cross-skill audit findings to skill factory trio

- skill-audit: remove contradictory skip clause in Step 2 (binary only)
- skill-improve: drop redundant "Fix the root" heading; keep specific directive
- skill-write: add section-rename guidance to body discipline step
- template SKILL.md: make Instructions heading an explicit FILL IN placeholder
- template README.md: remove "Invoke via your agent tool:" prefix to match convention

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

plugins/kyberforge/skills/skill-write/SKILL.md

@@ -69,6 +69,8 @@ Open `<destination-dir>/<skill-name>/SKILL.md`. Replace every `FILL IN:` placeho
 
 ### Body — include only what the agent lacks
 
+Rename `## FILL IN: <section-name>` to a heading that fits the skill's structure (e.g. `## Step 1`, `## Workflow`, `## Instructions`).
+
 Ask of every sentence: "Would the agent get this wrong without it?" Cut anything that answers "no."
 
 **Include:**