Git Submodule

Use this skill as the repository's Git submodule choice and operator-workflow anchor.

The job is not to dump every git submodule command in one blob. The job is to:

1. decide whether submodule is the right boundary at all,
2. choose one operating mode,
3. keep pinned-commit, detached-HEAD, and hosted-platform consequences explicit,
4. emit the next safe commands only for that mode.

Read references/decision-matrix.md first. Read references/update-and-detached-head.md when the request involves pointer updates, detached HEAD, or editing inside the submodule. Read references/ci-and-automation.md for CI/bootstrap expectations. Read references/mode-packets-and-hosted-constraints.md for mode-specific command packets and GitHub Pages / URL-drift constraints.