- All command-line tabs fork at startup; the last one is active and shown
black until its first frame maps, matching the existing README contract
that the last command's window appears immediately.
- Claim incoming toplevels by process group, not exact pid, so wrapped
commands (sh -c "foot -e htop") keep their own slot even though the
sh wrapper forks the real client.
- Closed tabs are fully removed: remove_app() compacts the array, frees the
slot, clears parent refs, and prefers the left neighbor as the successor
(right on explicit close, mirroring the old behavior on destroy).
- Black (pending) tabs are live slots: cycle/reorder walk them, activation
logs '[diag] active slot=N (black, awaiting map)', and Alt+Delete closes
one outright. A SIGCHLD-latched sweep drops black tabs whose whole
process group exits before ever connecting (e.g. /bin/false).
- The map-reveal rule keys on the scene node still being disabled, since a
slot's toplevel is set at claim time (before its map event).
- Update the standalone/headless and nested tests to wait for a mapped
frame (the startup tab is active before it maps, so the old 'no tab was
ever activated' wait no longer fires), and add two tests covering
Alt+Delete on a black active tab and the never-connecting-command sweep.
Andrew Hamilton
7f756ba8ee