fix(ci): gate unix-only mcp test imports for Windows clippy

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: ScriptedAlchemy

tests/mcp_suite/mcp_cli_serve_test.rs

@@ -2,6 +2,7 @@ use crate::common;
 
 #[cfg(unix)]
 use std::ffi::OsStr;
+#[cfg(unix)]
 use std::fs;
 use std::io::Write;
 #[cfg(unix)]

tests/mcp_suite/mcp_handler_test/lcm_test.rs

@@ -1,5 +1,6 @@
 //! `lcm_test` domain tests, split mechanically from `mcp_handler_test.rs`.
 
+#[cfg(unix)]
 use crate::common;
 use crate::support::*;
 use serde_json::{Value, json};