Adhere to claude agent skills spec format

[forefy]

PR to make this skill better pickable by claude code and similar

Skill.md must have a yaml frontmatter, where name is lowercase, and name needs to match the directory name.

This allows for correct extension of longer skills as when the file line count is over 500 we need to separate instructions to reference files. this is all from the claude docs.

Need this skills format compliance to list the skills in this repo on the Auditor Skill Registry ( https://forefy.com/skills )

[renlulu]

Codex batch review found one spec-compliance issue on this head.

Finding 1

[P2] The skill name now matches its directory, but the frontmatter still uses allowed-tools as a YAML sequence. The Agent Skills spec defines allowed-tools as a space-separated string, so registry/spec consumers expecting that schema can reject or mishandle this skill. Since this PR is specifically about Agent Skills/registry compliance, please keep the touched skill fully spec-shaped, for example allowed-tools: Read Grep Glob Bash Write.

[forefy]

@renlulu see fixes !