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

- validate.sh: move FAIL lines and failure summary to stdout; stderr
  reserved for fatal script errors only (missing SKILL.md, bad args)
- skill-audit SKILL.md: replace concrete plugins/kyberforge/skills/...
  example with abstract placeholder to fix meta-circularity
- skill-write SKILL.md: rephrase placeholder section-heading instruction
  to remove embedded FILL IN: from a code span, clearing validator false positive
- skill-improve SKILL.md: wrap Step 2 root-cause example in a text fence
- skill-write assets/templates/README.md: update Files table to individual-
  file rows so skill-audit can verify per-file coverage

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

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

@@ -73,7 +73,7 @@ Check each pattern is appropriate and correctly formed:
 - No non-spec files at the skill root (e.g. META.md, extra config files outside permitted directories)
 - Optional directories contain real content — not just unfilled placeholder READMEs
 - `README.md` present and accurately describes the skill and its files
-- No cross-plugin path references in SKILL.md, scripts/, references/, or assets/ — paths using `../`, `../../`, or absolute repo paths (e.g. `plugins/kyberforge/skills/...`) break when the plugin is installed to a cache; flag any found
+- No cross-plugin path references in SKILL.md, scripts/, references/, or assets/ — paths using `../`, `../../`, or absolute repo paths (e.g. `plugins/<plugin>/skills/<other-skill>/`) break when the plugin is installed to a cache; flag any found
 - `tests/` is exempt from the cross-plugin path check — test files are dev-only and may reference repo-level test infrastructure (e.g. a shared `tests/test_helper/`). This dependency must be declared in `tests/README.md`; flag if tests exist but `tests/README.md` is absent or does not document the dependency
 
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