fix(kyberforge): apply audit findings across skill factory trio

- skill-audit: promote internal-working gotcha to ## Gotchas section;
  narrow cross-plugin path check to exclude tests/ (dev-only, repo-level
  deps are expected); require tests/README.md to declare that dependency
- skill-write/skill-improve: reorder descriptions to lead with "Use when..."
  for consistency with skill-audit and the agentskills.io spec trigger pattern
- skill-write: add tests/README.md with self-contained bats setup instructions;
  remove cross-skill reference to skill-audit's tests/README.md

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

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

@@ -36,7 +36,8 @@ This skill produces its best output when you arrive with rich context:
 | `assets/templates/references/README.md` | Placeholder for reference docs |
 | `assets/templates/assets/README.md` | Placeholder for static assets |
 | `assets/templates/tests/README.md` | Placeholder for test files |
-| `tests/new-skill.bats` | Bats test suite for new-skill.sh — requires bats-support and bats-assert in the repo root's `tests/test_helper/` (see skill-audit's `tests/README.md` for setup) |
+| `tests/new-skill.bats` | Bats test suite for new-skill.sh |
+| `tests/README.md` | Setup instructions for bats-support and bats-assert test dependencies |
 
 ## Placement