Update dependencies

[stepchowfun]

Update Rust dependencies to their latest stable releases.

• Update Clap from 4.6.3 to 4.6.4. The release moves Clap's derive internals to Syn 3; this project does not use Syn directly, so no application code changes are required.
• Refresh compatible transitive dependencies in Cargo.lock, including libc 0.2.187 to 0.2.189, and consolidate Syn on 3.0.3. Reviewed release notes; their changes are compatible with this project's usage.
• Rust 1.97.1, nightly rustfmt 2026-07-18, GitHub Actions, and the 2026 copyright notice were already current.
• No dependencies are deprecated, archived, or obvious candidates for replacement/removal.

Status: Ready

Fixes: N/A