Add local cleanup skill

[Miyamura80]

Summary

• Copy global cleanup skill to local .claude/skills/cleanup/SKILL.md
• Ensures the cleanup automation is available within this repository's context.

[greptile-apps]

Greptile Overview

Greptile Summary

This PR adds a local copy of the cleanup skill to .claude/skills/cleanup/SKILL.md, making the git branch hygiene automation available within the repository context.

• Added comprehensive /cleanup skill that automates post-merge branch cleanup
• Includes safety guards: prevents deletion on main/master, checks for uncommitted changes, verifies branch is merged or closed
• Handles both merged branches (soft delete with -d) and closed PR branches (force delete with -D)
• Automates common maintenance tasks: prune stale refs, sync dependencies, garbage collection
• Correctly detects and uses uv sync as the primary dependency manager (aligns with repository's use of uv)
• Follows existing skill file structure with YAML frontmatter and markdown documentation

Confidence Score: 5/5

• This PR is safe to merge with no issues found
• The PR adds a well-structured documentation file with no code changes. The skill includes proper safety guards, follows repository conventions, and correctly prioritizes uv sync for dependency management (matching the project's use of uv). No logical, syntax, or security issues detected.
• No files require special attention

Important Files Changed

Filename	Overview
.claude/skills/cleanup/SKILL.md	Added comprehensive git cleanup automation skill with proper safety guards and dependency sync