GitLab CI Skill Review Pipeline

Problem/Feature Description

A DevOps engineer at a company using GitLab (self-hosted) needs to add automated skill review to their internal repository. The repository contains Tessl AI agent skills organized in a skills/ directory, with each skill having its own subfolder containing a SKILL.md file.

The team uses GitLab CI/CD for all their automation. They want the pipeline to review skills on merge requests, post results as MR comments, and maintain a score cache that gets committed to the main branch after merges. They also want the pipeline to automatically improve skills that don't score well by using the optimization feature.

The default branch is develop (not main), and they want the cache stored at ci/review-cache.json instead of the default location.

Output Specification

Produce:

1. A complete .gitlab-ci.yml file with all necessary stages and jobs.
2. A file called variables-guide.md explaining what CI/CD variables need to be configured and how.
3. A file called cache-init.json containing the properly formatted initial cache file.