fix(main): consume reuse_port param on Windows builds

SO_REUSEPORT is Unix-only; the parameter is only read inside the
#[cfg(not(windows))] block, so -D warnings fails the build with an
unused-variable error on Windows hosts while Linux CI stays green.

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

src/main.rs

@@ -100,6 +100,10 @@ fn make_socket(addr: &SocketAddr, reuse_port: bool) -> std::io::Result<Socket> {
     if reuse_port {
         socket.set_reuse_port(true)?;
     }
+    // SO_REUSEPORT is Unix-only; on Windows the flag is accepted but inert.
+    // Consume the parameter so `-D warnings` stays clean on Windows builds.
+    #[cfg(windows)]
+    let _ = reuse_port;
     // Disable Nagle's algorithm — send small responses (JSON, PROPFIND)
     // immediately instead of waiting up to 40ms for coalescing.
     socket.set_tcp_nodelay(true)?;