Agent Skills: git-commit

Use this skill whenever the user wants to commit changes, asks to split working-tree changes into multiple commits, or wants help organizing messy unstaged work — even if they don't explicitly say "commit". Writes Conventional Commits + Gitmoji messages. Strictly never runs `git add .`, `git add -A`, or `git commit -a`; commits only what the user has staged or what an approved grouping plan specifies.