Create GitHub Copilot agent skills for ArcGIS Enterprise operation

This is an umbrella issue (epic) for creating a set of specialized AI coding agent skills for ArcGIS Enterprise operation. The skills should simplify such tasks as:

1. **Workflow & Upstream Synchronization** - pulls upstream changes from public Esri repositories into private downstream repositories containing organization-specific modifications.
2. **Static Analysis & Vulnerability Management** - perform deep static analysis tailored to infrastructure-as-code (IaC) and automation scripts managing ArcGIS Enterprise deployments (such as Chef cookbooks, Terraform modules, and Python management scripts).
3. **CI/CD Pipeline Translation** - translate the GitHub workflows to other platforms, such as, GitLab CI/CD pipeline.

Start by decomposing the umbrella issue into its three workstreams: upstream synchronization, IaC and automation security analysis, and GitHub Actions translation to GitLab CI/CD. Review the repository's existing workflows, Terraform modules, and Python management scripts to define each skill's entry points and scope. Done means the required specialized skills are specified and implemented with clear validation for each workflow.

Written by the indexing model from the issue text.