Goal

• Simplify list_files
• Remove direct chrono dependency

Tasks

• Make list_files filename-only
• Update callers
• Remove direct chrono usage from Cargo.toml, src, and tests

Acceptance Criteria

• Netplan file loading and cleanup unchanged
• No direct chrono usage in Cargo.toml, src, and tests
• Relevant list_files and netplan tests pass

Non Goals

• Adding jiff