Run rustfmt on all Rust files to fix CI formatting checks.
This addresses pre-existing formatting inconsistencies across:
- cognitum-gate-kernel
- cognitum-gate-tilezero
- prime-radiant
- ruvector-* crates
- examples/benchmarks
- and other crates
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>