Restore writes tracked files back to their original locations.
Supports selective path restoration, force mode, and a confirm
callback for files where the on-disk mtime >= manifest timestamp
(truncated to seconds for cross-platform reliability). Creates
parent directories, recreates symlinks, and sets file permissions.
CLI: sgard restore [path...] [--force].
6 new tests (file, permissions, symlink, parent dirs, selective, confirm skip).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>