Add missing CertificateManager import for macOS

The perform_tls_interception function uses CertificateManager::is_ca_trusted()
on macOS but the import was missing from the main module (only present in tests).
This caused compilation to fail on macOS CI.

Added conditional import with #[cfg(target_os = "macos")] to match usage.

Author: ammar-agent

src/proxy_tls.rs

@@ -3,6 +3,8 @@ use crate::proxy::{
     create_connect_403_response_with_context, create_forbidden_response,
 };
 use crate::rules::Action;
+#[cfg(target_os = "macos")]
+use crate::tls::CertificateManager;
 use anyhow::Result;
 use bytes::Bytes;
 use http_body_util::{BodyExt, combinators::BoxBody};