pane: drive panes under zellij as well as tmux

The multiplexer is auto-detected ($ZELLIJ then $TMUX) and every pane
command works the same under both. Pane ids are self-identifying, so a
mixed set of tmux and zellij panes can be tracked at once. zellij has no
-l, so --size is ignored there, it always focuses a new pane (--detached
is emulated), and it leaves an EXITED husk behind that stop/reap now
clear. The pane tests skip on neither multiplexer rather than on no TMUX.

1 files changed, 4 insertions, 4 deletions

diff --git a/tests/test_trace_rpc.py b/tests/test_trace_rpc.py
index 1007385..b5a77a4 100644
--- a/tests/test_trace_rpc.py
+++ b/tests/test_trace_rpc.py
@@ -2,12 +2,12 @@
 """Trace integration over the RPC socket — the path an agent actually takes.
 
 The UI tests (test_trace_ui.py) drive the trace via in-process keystrokes and
-the Textual pilot. This one spawns a real tmux pane with ``--trace`` and drives
+the Textual pilot. This one spawns a real mux pane with ``--trace`` and drives
 every trace verb through the RPC socket, validating the JSON responses an agent
 would see. It exercises the serialization, the settle/timeout machinery, and
 the response shape that a driver depends on.
 
-Requires: tmux, IDA (idalib), and a trace. Records a fresh trace with the QEMU
+Requires: tmux or zellij, IDA (idalib), and a trace. Records a fresh trace with the QEMU
 tracer if built; falls back to /tmp/echotrace.0.log if present; skips with a
 message otherwise.
 
@@ -78,8 +78,8 @@ def stop_pane(sock, timeout=60):
 
 def main() -> int:
     global PASS, FAIL
-    if not os.environ.get("TMUX"):
-        print("  skip: not inside tmux (test spawns a pane)")
+    if not os.environ.get("TMUX") and not os.environ.get("ZELLIJ"):
+        print("  skip: not inside tmux or zellij (test spawns a pane)")
         return 0
 
     with tempfile.TemporaryDirectory() as tmp: