Phase 1: Add git ls-files integration to packager

[GargiGupta-io]

Adds helper functions to support git-aware packaging:

• _list_git_files(): Lists tracked and non-ignored untracked files
• _path_is_excluded(): Checks if a path should be excluded
• _write_git_files(): Recursively writes files to ZIP respecting exclusions

Part of #288 (Phase 1 of 4). Merge this first, then #290, #291, #292 in order.

[gemini-code-assist]

Code Review

This pull request introduces helper functions (_list_git_files, _path_is_excluded, and _write_git_files) to package Git-tracked and non-ignored files into a zip archive. The review feedback correctly identifies an issue where comparing relative file paths against absolute exclusion paths will cause exclusions to be silently ignored, and provides a robust solution using os.path.abspath.

[gemini-code-assist]

If base_dir is passed as a relative path (e.g., . or ./src), file_path will be constructed as a relative path. However, exclude_paths are absolute paths (as specified in the zip_working_dir docstring). Comparing a relative path with an absolute path using os.path.normpath will fail to match, causing exclusions to be silently ignored.

Converting path to an absolute path using os.path.abspath before performing the comparison ensures that exclusions are correctly respected regardless of whether base_dir is relative or absolute.

Suggested change

	def _path_is_excluded(path: str, exclude_paths: set[str]) -> bool:
	if not exclude_paths:
	return False
	normalized_path = os.path.normpath(path)
	return any(
	normalized_path == excluded or normalized_path.startswith(excluded + os.sep)
	for excluded in exclude_paths
	)
	def _path_is_excluded(path: str, exclude_paths: set[str]) -> bool:
	if not exclude_paths:
	return False
	abs_path = os.path.abspath(path)
	return any(
	abs_path == excluded or abs_path.startswith(excluded + os.sep)
	for excluded in exclude_paths
	)