A pty/ctl winsize gives a terminal two rows at least, so it no longer reads busy for ever

A one-row pty loses the prompt's input mark as soon as the prompt wraps,
and busy detection never sees the shell idle again. Placement already
keeps a new terminal at tag + 2 rows; a winsize write now keeps the pty
at two. A pane dragged down to one body row keeps a one-row pty, since
a taller pty than the pane shows would put its cursor below the pane.

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

1 files changed, 4 insertions, 1 deletions

diff --git a/src/pardes.zig b/src/pardes.zig
index dd9d91c8..6341de91 100644
--- a/src/pardes.zig
+++ b/src/pardes.zig
@@ -6596,7 +6596,10 @@ pub const Pardes = struct {
                 pane.tag_top = @intCast(@min(top, lines - pane.tag_rows));
             } else pane.tag_top = 0;
             const cols = @max(1, r.w -| config.GUTTER);
-            const rows = @max(1, r.h -| pane.tag_rows); // the tag steals the top rows
+            // The tag steals the top rows. The pty is what the pane shows,
+            // even one row dragged short: a taller pty would put its cursor
+            // below the pane (only winsize keeps two, ctlfs.pty).
+            const rows = @max(1, r.h -| pane.tag_rows);
             // A terminal's pty follows its pane down to a row, whatever the
             // resize; only a folded one keeps the size it had, and one not
             // placed yet the grid it was made with.