chore: fix stale skill-frontmatter and check-manifests references

c8a7c9e folded the skill-frontmatter hook into skill-size-check but
left validate.sh's FAIL messages, skill-author's create.md, and the
skill template's frontmatter comment naming the deleted hook as the
enforcer -- misleading for anyone tracing a FAIL back to the gate that
raises it.

f11b645 swept check-manifests references but missed a hand-authored
"Local hooks in this repo" table in the git plugin's vendored
pre-commit research doc, which still listed both check-manifests and
skill-frontmatter as active hooks.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YR2CjVumUbEGWcMikcoXBD

plugins/kyberforge/skills/skill-audit/scripts/validate.sh

@@ -1291,7 +1291,7 @@ else:
 
 # --- ADR-0022: metadata.version is mandatory -------------------------------
 # FAIL, not SUGGESTION, and the tier is set by the gate rather than by taste.
-# `.pre-commit-config.yaml`'s `skill-frontmatter` hook REJECTS a SKILL.md with
+# `.pre-commit-config.yaml`'s `skill-size-check` hook REJECTS a SKILL.md with
 # no `metadata.version`, and rejects a value that is not three-part semver.
 # skill-author's Step 4 says to run this audit and "resolve every FAIL", so any
 # tier below FAIL lets that step report done on a skill the commit gate then
@@ -1316,7 +1316,7 @@ metadata_block = fm_data.get('metadata') if isinstance(fm_data, dict) else None
 
 if not isinstance(metadata_block, dict) or metadata_block.get('version') is None:
     fail("frontmatter has no metadata.version — ADR-0022 makes it mandatory for "
-         "every skill, and the skill-frontmatter pre-commit hook rejects the file "
+         "every skill, and the skill-size-check pre-commit hook rejects the file "
          "without it. Add `metadata:` / `  version: \"1.0.0\"` (new skills start "
          "at \"0.1.0\")")
 else:
@@ -1330,7 +1330,7 @@ else:
         ok(f"metadata.version present: '{version_text}' (ADR-0022)")
     else:
         fail(f"metadata.version '{version_text}' is not three-part semver — the "
-             f"skill-frontmatter pre-commit hook rejects it. Use MAJOR.MINOR.PATCH, "
+             f"skill-size-check pre-commit hook rejects it. Use MAJOR.MINOR.PATCH, "
              f"e.g. \"1.0.0\"")
 
 # SKILL.md size ceilings (agentskills.io skill-authoring.md: 500 lines,