Git command safety regression

This self-contained regression uses only Python 3's standard library and Git. It creates disposable repositories in a Python-managed temporary directory, disables global/system Git configuration, signing, and hooks, then removes the temporary directory automatically.

Run it from the repository root:

bash labs/git-command-safety/test.sh

It verifies the exact command patterns documented in the paired articles.

Scenario	Documented command pattern	Assertion
A workspace already has staged, unstaged, and untracked work	git status --porcelain; any output stops the rewrite or cleanup flow	The branch name, HEAD, Index tree, tracked file contents, untracked file, and status remain unchanged.
A task owns complete tracked paths while unrelated work is already staged	git commit --only -m "..." -- <agent-owned-paths>	The commit contains only the named task path; unrelated staged, unstaged, and untracked content remains in place.
A local unpushed large commit must be split	git reset --soft HEAD~1, then git reset, then git add -p	The counterexample proves that add -p immediately after a soft reset leaves every hunk staged. The corrected flow commits only the selected hunk.
The integration branch is master	git switch <integration-branch>	git switch main fails without changing state; substituting master succeeds.

The test only establishes local Git behavior in the temporary repositories. Remote authorization, protected-branch policies, hooks, and team workflow rules still require the actual repository's checks.

中文说明

这是一个只用 Python 3 标准库和 Git 的自包含回归实验。它在 Python 管理的临时目录创建仓库，隔离系统和全局 Git 配置、签名与 hooks，结束时自动移除临时目录。

从仓库根目录执行：

bash labs/git-command-safety/test.sh

实验对应中英文文章中的命令流程：工作区已有 staged、unstaged、untracked 内容时，git status --porcelain 有输出就停止重写或清理流程，并断言分支、HEAD、Index、文件内容和状态均未改变；完整任务路径用 git commit --only -m "..." -- <agent-owned-paths> 提交时，保留其他已有编辑；soft reset 后先执行 git reset 再 git add -p，才能只提交选中的 hunk；把占位符替换成实际集成分支 master 时，流程不依赖 main。

实验只证明临时本地仓库中的 Git 行为。实际仓库的远端授权、受保护分支、hooks 和团队规则仍需要单独确认。