Update dependencies in Cargo.lock and Cargo.toml; fix certificate gen…

[unclesp1d3r]

Summary

This PR updates dependencies to resolve cargo-audit findings in the 1.0.0 release, specifically addressing issues with ring (via rcgen) and tracing-subscriber.

Changes

Dependencies

• Bumped rcgen from 0.11.3 → 0.14.5
  • Removes transitive ring 0.16.20 dependency (unmaintained / vulnerable)
  • Required minor changes in src/transport/tls.rs due to API updates
• Bumped tracing-subscriber from 0.3.19 → 0.3.20
  • Resolves ANSI escape sequence injection issue

Code Updates

• Adjusted TLS handling to match rcgen 0.14.x API:
  • generate_simple_self_signed() now returns CertifiedKey
  • Updated certificate and private key serialization calls

Verification

• cargo audit passes cleanly
• cargo check compiles successfully
• cargo test --lib all tests pass
• Dependency count reduced (190 → 178)

Notes

These upgrades should be backwards-compatible for users of this crate, while addressing security warnings and reducing dependencies.