fix(pty): always set TERM/COLORTERM for spawned shells

A GUI/launchd-spawned daemon has no TERM in its environment, so child shells
inherited none and tput/zsh/ncurses failed ('tput: No value for $TERM').
The PTY now defaults TERM=xterm-256color and COLORTERM=truecolor (matching
xterm.js) unless the caller already provides them. Adds a regression test.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/spacesh-pty/src/lib.rs

@@ -38,6 +38,16 @@ impl PtyHandle {
             cmd.arg(a);
         }
         cmd.cwd(&spec.cwd);
+        // Guarantee a terminal environment even when the daemon was launched
+        // without one (GUI/launchd have no TERM, which breaks tput/zsh/ncurses).
+        // xterm.js renders an xterm-256color/truecolor terminal. Caller-provided
+        // values in spec.env win.
+        if !spec.env.iter().any(|(k, _)| k == "TERM") {
+            cmd.env("TERM", "xterm-256color");
+        }
+        if !spec.env.iter().any(|(k, _)| k == "COLORTERM") {
+            cmd.env("COLORTERM", "truecolor");
+        }
         for (k, v) in &spec.env {
             cmd.env(k, v);
         }
@@ -125,6 +135,19 @@ mod tests {
         assert!(text.contains("SPACESH_OK"), "got: {text:?}");
     }
 
+    #[tokio::test]
+    async fn term_is_set_even_without_inherited_env() {
+        // Clear TERM in the parent to emulate a GUI/launchd-spawned daemon.
+        std::env::remove_var("TERM");
+        let mut handle = PtyHandle::spawn(shell_spec("printf %s \"$TERM\"")).unwrap();
+        let mut collected = Vec::new();
+        while let Some(chunk) = handle.output.recv().await {
+            collected.extend_from_slice(&chunk);
+        }
+        let text = String::from_utf8_lossy(&collected);
+        assert!(text.contains("xterm-256color"), "got: {text:?}");
+    }
+
     #[tokio::test]
     async fn resize_does_not_error() {
         let handle = PtyHandle::spawn(shell_spec("sleep 0.2")).unwrap();