Pre-push clippy gate fails: 172 unwrap_used in test code

[noahgift]

Issue

The pre-push hook fails due to 172 clippy unwrap_used warnings in test code (src/sync.rs tests), preventing any pushes.

This was likely introduced by a Rust toolchain update enabling stricter clippy defaults for test targets.

Impact

Blocks ALL pushes including bug fixes (e.g., #17 --block-size fix).

Fix Options

1. Add #[allow(clippy::unwrap_used)] to test modules
2. Replace unwrap() with expect() in test code
3. Adjust clippy.toml to allow unwrap in tests

Found during kaizen dogfooding push.