cli: terminal app follow-up, narrow-terminal guard test, hidden-box way out and width tests (#1562)

Row 69, built by Darkwing, approved by Dewey (comment 28048) and Filbert
(comment 28055) on manifest c68e6582. Sage gate on c6711453: cli 123/0,
queue 150/0, every scripts suite green.

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

packages/cli/README.md

@@ -129,11 +129,16 @@ and nothing else.
   action and target, what the choice authorizes, the task, your choice
   and the `[y/N]` question stay. The cut line points to `mosaic inbox
   --json`. When even those lines don't fit, the box says only "Too small
-  to show this decision. Any key answers No." `y` resolves only while the
-  frame shows the whole box apart from the cut, and the app checks the
-  size at each key, so a terminal shrunk after the question appeared
-  answers No. A gated decision with a task needs 20 rows at 80 columns
-  (21 with a cut question), and 29 rows at 40 columns.
+  to show this decision. Any key answers No. Resize, or use mosaic
+  decide.", and the status line says "Too small to confirm here." instead
+  of promising a `y`. `y` resolves only while the frame shows the whole
+  box apart from the cut, and the app checks the size at each key, so a
+  terminal shrunk after the question appeared answers No. Under 40
+  columns or 10 rows the app shows only the too-small screen, however
+  tall the terminal is. How many rows a box needs depends on its lines.
+  For example, a plain gated decision with a task needs 20 rows at 80
+  columns (21 with a cut question) and 29 rows at 40 columns; one with
+  longer lines needs more.
 - The transport is the verbs' `spawnSync` child, so the screen does not
   redraw while a read is in flight (up to its 30 s timeout).
 - On quit, end of input, SIGTERM, SIGINT, SIGHUP or an error (one in a