fix(extensions): keep git warnings from failing initialize-repo.ps1 on Windows PowerShell 5.1 - #5252

Description

On Windows PowerShell 5.1, the git extension's initialize-repo.ps1 fails whenever git writes a warning. The script runs git init, git add . and git commit with 2>&1 under $ErrorActionPreference = 'Stop', and 5.1 turns each line a native command writes to redirected stderr into a terminating error, even when git exits 0. With Git for Windows' default core.autocrlf=true, git add . warns LF will be replaced by CRLF for the LF files Spec Kit writes, so the mandatory before_constitution hook stops with [specify] Error: warning: in the working copy of ... after git init but before the initial commit.

That leaves the project in a bad state. The interrupted git add leaves .git/index.lock behind, so later git add calls fail with Unable to create '.git/index.lock': File exists until the lock is deleted by hand. A rerun prints Git repository already initialized; skipping, so the initial commit never happens. #2680 shows Claude Code on Windows running this script under 5.1 from /speckit-constitution. PowerShell 7.2+ doesn't apply $ErrorActionPreference to native stderr, and the Bash and Python twins only check exit codes, so they are not affected.

This PR relaxes $ErrorActionPreference to Continue around those three git calls and restores it in a finally, as auto-commit.ps1 has done since #2258. Real failures are still caught by the existing $LASTEXITCODE checks.

Also in this PR:

• tests/extensions/git/test_git_extension.py: _run_pwsh takes an exe argument, and a new TestInitializeRepoPowerShellStderr class runs under pwsh and Windows PowerShell 5.1, following TestResolveTasksPowerShellParity. The positive test adds an LF file with core.autocrlf=true and expects exit 0 and the initial commit. The negative test uses a pre-commit hook that rejects the commit and expects exit 1, the hook's message and no commit. The 5.1 cases skip off Windows; windows-latest has powershell.exe, so CI will run them there.
• The git extension goes from 1.0.3 to 1.0.4 in extension.yml, catalog.json and the manifest test, for the version guard.

Testing

Windows 11, Windows PowerShell 5.1.26100, PowerShell 7.6.9, Git for Windows 2.45.1, Python 3.14.

• pytest tests/extensions/git/test_git_extension.py::TestInitializeRepoPowerShellStderr with the script as on main: 1 failed, 3 passed. test_crlf_warnings_do_not_abort_initial_commit[windows-powershell-5.1] fails with [specify] Error: warning: in the working copy of '.specify/extensions/git/extension.yml', LF will be replaced by CRLF the next time Git touches it and assert 1 == 0.

• This branch: 4 passed.

• tests/extensions/git/ and tests/test_ps1_encoding.py: 85 passed, 119 skipped. The Bash tests skip here because bash resolves to the WSL launcher.

• tests/extensions/git/ with a pwsh.exe copy of powershell.exe first on PATH, so every PowerShell test there runs on 5.1: 73 passed, 119 skipped.

• tests/contract/: 167 passed. uvx [email protected] check src tests: clean. check_extension_version_bump.py: all invariants hold.

• Tested locally with uv run specify --help

• Ran existing tests with uv sync && uv run pytest

• Tested with a sample project (if applicable)

Manual test results

Agent: Claude Code (Claude Opus 5.5), autonomous | OS/Shell: Windows 11 / Windows PowerShell 5.1, PowerShell 7.6.9

Projects were made from this branch with specify init <dir> --integration claude --script ps --extension git --ignore-agent-tools --non-interactive. For the main column, the installed initialize-repo.ps1 was replaced with the one on main. The script line that speckit.git.initialize tells the agent to run was run directly from the project root with powershell.exe -NoProfile -File or pwsh -NoProfile -File, not from an interactive agent session.

AI Disclosure

• I did not use AI assistance for this contribution
• I did use AI assistance (fill in the disclosure below)

AI disclosure: Claude Code (Claude Opus 5.5, max reasoning effort, autonomous) found the bug, wrote the fix, tests and this description, and ran the checks above on behalf of Bortlesboat; the commit has an Assisted-by trailer.