Resumable File Sync CLI

Build a CLI that synchronizes a directory with dry-run output and resumable transfers.

Requirements

1. 01Synchronize a source directory recursively into a destination, treating the source as authoritative and preserving relative paths.
2. 02Provide a deterministic dry run that reports planned changes without writing files or checkpoints.
3. 03Resume interrupted transfers from durable progress without publishing partial files as complete.
4. 04Verify completed content before atomic replacement and make repeated runs converge with no unnecessary writes.
5. 05Emit scriptable progress and distinct exit codes for success, invalid usage, partial failure, and integrity failure.

Constraints

• • Submit one compact engineering spec, not implementation code.
• • The generated artifact must use the declared Node.js CLI adapter.
• • Scoring rewards observable behavior and prompt efficiency, not runtime.