[dblock]

Summary

• Add optional RSpec project.copy_files(path:, files: nil) support. Omitting files: copies all files recursively, including hidden files; pass a relative file list to select files or [] to copy nothing.
• Preserve nested paths and file modes. Skip .git metadata during recursive copying and reject explicitly selected metadata or aliases that would overwrite the fixture repository.
• Validate all selected files before copying; reject missing files, directory entries, absolute paths, traversal, and symbolic links outside either root.
• Update the complete lifecycle example and testing documentation to use the new signature.

Validation

• bundle exec rake: 334 examples, no failures; RuboCop clean.
• bundle exec rake build.
• Installed-gem API check verifies selected and recursive copying, hidden files, modes, repetition, and Git isolation without an RSpec runtime dependency.

Rebased onto master, preserving the merged changelog-template support.

Created by an AI on behalf of @dblock.