fix: use TCP instead of Unix socket on Windows in dashboard relay (#1038)

`relay_command_to_daemon` in stream.rs used `tokio::net::UnixStream`
unconditionally, which doesn't compile on Windows. Add platform-
conditional code matching the existing pattern in daemon.rs and
connection.rs: Unix sockets on unix, TCP on Windows.

cli/src/connection.rs

@@ -144,7 +144,7 @@ fn get_port_path(session: &str) -> PathBuf {
 }
 
 #[cfg(windows)]
-fn get_port_for_session(session: &str) -> u16 {
+pub fn get_port_for_session(session: &str) -> u16 {
     let mut hash: i32 = 0;
     for c in session.chars() {
         hash = ((hash << 5).wrapping_sub(hash)).wrapping_add(c as i32);