fix: normalize Windows backslash paths to forward slashes for git

[quyentho]

Summary

• On Windows, path.relative() returns backslash-separated paths (e.g. .vscode\launch.json), but git requires forward slashes on all platforms
• Without this fix, all git index operations fail on Windows with errors like error: Invalid path '.vscode\launch.json'
• Added a toGitPath() helper that converts backslashes to forward slashes, applied to all relative paths before they are passed to git in hunkwiseGit.ts

Affected operations

All HunkwiseGit methods that compute a relative path from path.relative():

• snapshot() — stage a single file baseline
• snapshotBatch() — stage multiple file baselines at once
• removeFile() — remove a single baseline
• removeFileBatch() — remove multiple baselines at once
• renameFile() — rename a baseline entry
• getBaseline() — read a baseline from the index

Test plan

• Enable hunkwise on a Windows machine
• Edit a tracked file externally — baseline should be staged without "Invalid path" errors in the output log
• Accept / Discard a hunk — should complete successfully
• Verify the extension output log is free of error: Invalid path entries

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Fixes Windows failures in the extension’s internal git repo by ensuring file paths passed to git use forward slashes (git pathspec format), even when path.relative() returns backslash-separated paths on Windows.

Changes:

• Added toGitPath() helper to convert \ to / for git compatibility.
• Applied toGitPath() to all relative-path values derived from path.relative() before they’re used in git commands (snapshot, batch ops, remove, rename, getBaseline).
• Normalized parsed ls-files output paths through toGitPath() as well.

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[Copilot]

There are existing unit tests for HunkwiseGit, but this Windows-specific path fix isn’t covered. Please add a test that exercises the new backslash→slash conversion (e.g., temporarily monkeypatch path.relative to return a value with \\ and assert snapshot()/getBaseline() (and ideally removeFile/renameFile) still succeed). This will prevent regressions while running the test suite on non-Windows CI.

[Copilot]

toGitPath() duplicates the same backslash-to-slash normalization logic that already exists elsewhere (e.g. FileWatcher uses .replace(/\\/g, '/')). Consider centralizing this into a shared path utility (and reusing it from both places) so future path-handling fixes don’t diverge.

Suggested change

	* Convert Windows backslash paths to forward slashes for git compatibility.
	* Git expects forward slashes on all platforms.
	*/
	function toGitPath(p: string): string {
	return p.replace(/\\/g, '/');
	* Convert paths to git-compatible forward-slash form.
	* Git expects forward slashes on all platforms.
	*/
	function toGitPath(p: string): string {
	return normalizePath(p);