A command line runs as its own command pane unless it is clicked at a shell's prompt

A middle click, an exec write or a tag word that no builtin knows was typed
into some terminal for the pane's directory, sharing whatever state that
shell was in and answering nothing, so a misspelling vanished into a shell.
Now only a line clicked at an interactive terminal's prompt is typed there.
From anywhere else it runs as a command pane: a terminal whose child is
$SHELL -c the line in the pane's directory, full emulation, which shows its
output and then exit N from the host's reaping of the child, and stays. A
finished command pane is the next command's for its directory, which runs
below what it showed after a '% line' line (acme appends to +Errors and never
clears it, util.c:213); a running one gets a second pane. Kill ends a command
pane's whole process group, the log records run and exit, exec reads back the
command pane's serial, and a line is at most 1 KB, read off the pane as the
host forks rather than carried in every spawn effect. ttyForDir's search for
a free shell is gone. The goldens of chordcut, cmdword and layout-open change
where a file's exec now opens a command pane, and ttytaken is rewritten to
exec from the terminal itself; docs/open-questions.md records the decision.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 7 insertions, 7 deletions

diff --git a/test/snapshots/chordcut.golden b/test/snapshots/chordcut.golden
index b814d888..42725e42 100644
--- a/test/snapshots/chordcut.golden
+++ b/test/snapshots/chordcut.golden
@@ -30,11 +30,11 @@
 == snap cancelexec grid=120x31 cursor=25,8
 |8:      2  2echo B''OO g.txt
 == snap execafter grid=120x31 cursor=25,8
-|3:     f.txt                                                     ls
-|4:   BOO                                                         f.txt  g.txt
-|7:      1 line 1                                          Exec
+|6:    /tmp/pardes-snap/chordcut/cwd/f.txt * Save Tty Collapse D   /tmp/pardes-snap/chordcut/cwd (echo B''OO) exit 0 Kill Sa
+|7:      1 line 1                                          Exec   BOO
+|8:      2  2echo B''OO g.txt                                     exit 0
 == snap cancellook grid=120x31 cursor=25,8
-|7:      1 line 1
+|7:      1 line 1                                                 BOO
 == snap lookafter grid=120x31 cursor=7,13
 |12:    /tmp/pardes-snap/chordcut/cwd/g.txt Save Tty Collapse Del
 |13:      1 line 1
@@ -44,10 +44,10 @@
 |0: 0-70 #b2c3b8,#1d2824, 71-119 d,#1d2824,
 |1: 0-1 #ffffff,#887455, 2-2 d,#26362d, 3-34 #becfc4,#26362d, 35-59 d,#26362d, 60-61 #ffffff,#887455, 62-62 d,#1d2824, 63-94 #b2c3b8,#1d2824, 95-119 d,#1d2824,
 |2: 0-1 #ffffff,#496656, 2-2 d,#1d2824, 3-32 #b2c3b8,#1d2824, 33-35 #d3b0d9,#1d2824, 36-59 #b2c3b8,#1d2824, 60-61 #ffffff,#496656, 62-62 d,#1d2824, 63-92 #b2c3b8,#1d2824, 93-95 #d3b0d9,#1d2824, 96-119 #b2c3b8,#1d2824,
-|3: 0-0 d,#152019, 1-1 d,#0d1410, 2-8 #e5eee5,#0d1410, 9-59 d,#0d1410, 60-60 d,#608269, 61-61 d,#0d1410, 62-119 #e5eee5,#0d1410,
+|3: 0-0 d,#608269, 1-1 d,#0d1410, 2-59 #e5eee5,#0d1410, 60-60 d,#608269, 61-61 d,#0d1410, 62-119 #e5eee5,#0d1410,
 |4: 0-0 d,#608269, 1-1 d,#0d1410, 2-59 #e5eee5,#0d1410, 60-60 d,#608269, 61-61 d,#0d1410, 62-119 #e5eee5,#0d1410,
-|5: 0-0 d,#152019, 1-59 d,#0d1410, 60-60 d,#608269, 61-119 d,#0d1410,
-|6: 0-1 #ffffff,#496656, 2-2 d,#1d2824, 3-32 #b2c3b8,#1d2824, 33-37 #d3b0d9,#1d2824, 38-59 #b2c3b8,#1d2824, 60-60 d,#608269, 61-61 d,#0d1410, 62-119 #e5eee5,#0d1410,
+|5: 0-0 d,#608269, 1-59 d,#0d1410, 60-60 d,#608269, 61-119 d,#0d1410,
+|6: 0-1 #ffffff,#496656, 2-2 d,#1d2824, 3-32 #b2c3b8,#1d2824, 33-37 #d3b0d9,#1d2824, 38-59 #b2c3b8,#1d2824, 60-61 #ffffff,#496656, 62-62 d,#1d2824, 63-119 #b2c3b8,#1d2824,
 |7: 0-0 d,#608269, 1-1 d,#0d1410, 2-6 #59675c,#0d1410, 7-12 #e5eee5,#0d1410, 13-59 d,#0d1410, 60-60 d,#608269, 61-61 d,#0d1410, 62-119 #e5eee5,#0d1410,
 |8: 0-0 d,#608269, 1-1 d,#0d1410, 2-6 #59675c,#0d1410, 7-24 #e5eee5,#0d1410, 25-59 d,#0d1410, 60-60 d,#608269, 61-61 d,#0d1410, 62-119 #e5eee5,#0d1410,
 |9: 0-0 d,#608269, 1-1 d,#0d1410, 2-6 #59675c,#0d1410, 7-12 #e5eee5,#0d1410, 13-59 d,#0d1410, 60-60 d,#608269, 61-61 d,#0d1410, 62-119 #e5eee5,#0d1410,