Add Golden GitHub Loop slash command

[kvandre12-commits]

Summary

Add /github-loop <task>, a plugin-provided slash command that forwards a disciplined coding and pull-request mission to the active agent.

The workflow codifies the repository-maintenance loop:

1. inspect with list_files, grep, and read_file,
2. reproduce the failure,
3. patch narrowly with structured file tools,
4. run focused tests and independent quality checks,
5. inspect the final diff and working-tree state,
6. commit, push a feature branch, and open or update a PR with gh.

Safety boundaries

The generated mission explicitly preserves unrelated work and contributor authorship. It prohibits force-pushes, direct pushes to main, history rewrites, merges, secret exposure, and production mutations. It also carries the explicit worktree-context rule: after git worktree add, use a second shell call with the new cwd or use git -C.

Design

The plugin deliberately does not duplicate agent or tool orchestration. It returns core's CustomCommandResult, so the existing command dispatcher forwards the generated workflow as user input to the normal agent runtime.

User-facing help and usage text use a plugin-owned i18n catalog. The model-facing workflow remains untranslated.

Usage

/github-loop Reproduce and fix issue #123
/github-loop Refresh PR #456 and address its failing check

Validation

• 19 focused, i18n, dispatcher, and plugin-lock tests passed
• Ruff correctness checks passed
• Ruff formatting check passed
• git diff --check passed
• wheel build passed
• wheel contents include the plugin module and en-US catalog