Add UDP DNS receive timeouts and random query IDs

[ryanfowler]

Summary

• Thread DNS timeout values through custom UDP lookup paths so unresponsive resolvers cannot hang indefinitely.
• Add a shared DNS utility for random u16 query IDs and a 5s default UDP receive timeout when no request/connect timeout is set.
• Update both resolver and DNS inspection code to use the shared helpers and tokio::time::timeout around recv.
• Add focused unit coverage for UDP timeout behavior and keep existing DNS resolution paths intact.

Testing

• cargo fmt
• cargo clippy --locked --all-targets --all-features -- -D warnings
• cargo test --all-features
• cargo test --all-features --test integration -- --test-threads=1