Close websocket v1 gaps and add logger interceptor

[fannnzhang]

Summary

• close the remaining v1 websocket gaps on this branch, including the fastwebsockets engine integration and websocket listener/test coverage
• add a built-in OkHttp-style LoggerInterceptor with LogLevel::{Basic, Headers, Body}
• pretty-print JSON bodies with serde_json::to_writer_pretty, redact sensitive headers by default, and omit streaming or oversized bodies instead of fully draining them
• update the logging example and README to document the new interceptor and its HTTP-only scope

Validation

• cargo test -p openwire --lib logging::tests --features websocket
• cargo check -p openwire --example logging_interceptor --features websocket
• cargo check -p openwire --all-targets --features websocket