closes#62
when you open a new Zellij pane, the shell inherits Iris’s environment
variables, so it thinks Iris is already running. But the pane doesn't
inherit the underlying connection (FD 13), so suggestions silently fail
into a dead pipe
the old code only checked for `tmux` by process name, ignoring Zellij
completely
- Fixed:
instead of checking for specific app names, Iris now tracks the active
terminal device (`IRIS_TTY`)
if a new shell detects that it's on a different `TTY` than Iris, it
clears the stale environment variables so Iris can start fresh. The
`IRIS_PID != PPID` check prevents Iris from trying to re-exec itself
when spawning sub-shells.
```sh
if [ -n "$IRIS_PID" ] && [ "$IRIS_PID" != "$PPID" ] && [ "${TTY:-$(tty 2>/dev/null)}" != "$IRIS_TTY" ]; then
unset IRIS_PID IRIS_IS_CHILD IRIS_FD IRIS_TTY
fi
```
VERSE
fc1634b007