feat: add CI linter to enforce skill anatomy standards automatically

[LorenzaVolponi]

Problem
As the repository grows, ensuring every contributed skill follows the strict anatomy defined in docs/skill-anatomy.md (YAML frontmatter, required sections, naming conventions) becomes a manual and error-prone review process.

Proposed Solution
I propose adding a lightweight GitHub Action that runs on every Pull Request. It will automatically validate any modified or added SKILL.md files to ensure they have:

Valid YAML frontmatter with name and description.
The name matches the directory name.
Required sections exist (## Overview, ## When to Use, ## Verification).
This offloads the mechanical review from maintainers and guarantees structural consistency.

If this sounds like a good addition, I'd be happy to submit a PR implementing this validation script and workflow.

[rajpratham1]

This seems like a solid improvement. As repositories scale, maintainers often end up spending time on structural checks instead of reviewing the actual content and quality of contributions.

One thing that might be worth considering is making the validator focus only on changed SKILL.md files in a PR to keep runs fast and avoid unnecessary noise. It could also provide clear error messages pointing contributors to the exact section of skill-anatomy.md that failed validation.

Overall, automating these consistency checks would likely make reviews more efficient and reduce back-and-forth on formatting issues.