Run a line at a terminal's prompt through pty/run and read how it ended

/pane/<n>/pty/run takes factotum's rpc shape: write one line on an open,
read the answer on that same open. The answer is exit N once the command
ended and the shell is back at a prompt; busy at once when a command runs,
text is typed at the prompt, or the shell has not drawn its first prompt;
error not run when the shell refused the line without running it (fish on
a syntax error keeps it on the prompt, so it is taken back with Ctrl-U);
error shell gone when the pane closes or its shell is replaced; error no
prompt marks for a shell pardes could not instrument.

The end comes from the shell's OSC 133 marks. ghostty parses D's exit
status and drops it, so the stream now runs through a handler that wraps
ghostty's and follows prompt -> input -> running -> done. The marks pardes
injects into bash and fish carry aid=pardes and only those count, so fish
4's own marks (which doubled ours), a nested shell's, and a stray 133;D in
printed output are ignored.

Checked end to end against real bash and fish: false, exit 7, a syntax
error, sleep, busy while running, and the pane closing mid-command.

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

1 files changed, 1 insertions, 0 deletions

diff --git a/src/fs.zig b/src/fs.zig
index fef4ffe1..c35322b6 100644
--- a/src/fs.zig
+++ b/src/fs.zig
@@ -1238,6 +1238,7 @@ pub const Namespace = struct {
     node_name: [16]u8 = undefined,
     os_paths: std.ArrayList(OsPath) = .empty,
     snapshots: [tree.screen.snapshot_slots]tree.screen.Snapshot = @splat(.{}),
+    runs: [tree.pty.run_slots]tree.pty.Run = @splat(.{}),
     out: std.ArrayList(u8) = .empty,
     panes: [MAX_PANES]tree.pane.State = @splat(.{}),
     listeners: u16 = 0,