size says its limits, keeps every pane its rows, and ptys follow their panes

size refused an out-of-range line without saying the range, took a size
too small for the panes (leaving bodies of no rows), and a terminal
squeezed to its tag kept a pty of its old size. The refusal now names
20x6 to 4096x4096 (a bare size is EINVAL like any malformed line), a size
that would leave any pane less than its tag and 2 rows is refused and
undone, and a terminal's pty is resized with its pane down to one row
(only a folded or unplaced one keeps its grid).

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

1 files changed, 3 insertions, 1 deletions

diff --git a/docs/fs.md b/docs/fs.md
index cf6acb60..03851d8d 100644
--- a/docs/fs.md
+++ b/docs/fs.md
@@ -106,7 +106,9 @@ Existing Plan9port/v9fs clients need a userspace bridge for QUIC.
              which makes its column the active one as a click there would
 /ctl         the settings, one a line as a write takes them; write a setting or a session builtin;
              `size <cols> <rows>` sets the screen of a session no frontend is attached to
-             (`--detach`, 80x24 until then; refused while a frontend owns the size)
+             (`--detach`, 80x24 until then; refused while a frontend owns the size),
+             from 20x6 to 4096x4096, and refused when the panes it has would not each
+             keep their tag and 2 rows; a terminal's pty follows its pane on every resize
 /commands    every builtin: word, `arg` if it takes one, `root` or `pane` (the ctl that takes it), a setting's values
 /layout      one line per column, left to right: serial index x width current|notcurrent
              empty|full pane-serials...; then active <serial>: the active column, where