Update dependencies

[stepchowfun]

Update Clap from 4.6.3 to 4.6.4 and refresh transitive lockfile entries (clap_derive 4.6.3 → 4.6.4, libc 0.2.187 → 0.2.189, and syn 2.0.119 → 3.0.3). Clap 4.6.4’s only change is its internal migration to syn 3; Typical does not use syn directly, so no compatibility adaptation is needed. The libc updates are additive/fix releases.

Remove the dormant pad 0.1.6 dependency (last crate release in 2019) and its obsolete unicode-width 0.1 transitive dependency. Its sole use right-aligned numeric line numbers and is replaced directly with Rust’s standard formatting syntax, preserving output while reducing dependencies. No other dependency-health issue requires a migration.

Rust 1.97.1, nightly rustfmt 2026-07-18, GitHub Actions, and the 2026 license year were already current. This repository has no git submodules.

Native verification passed with Rust 1.97.1 (cargo build, 215 unit tests, and Clippy). Canonical verification passed with toast build, toast test_units, toast test_rust_integration, toast test_typescript_integration, and toast lint, including Rust and TypeScript generator scenarios, tagref, shellcheck, Clippy, and rustfmt.

Status: Ready

Fixes: N/A