os/v3/puppy: a console-TUI confirmation loses the row that says how to answer it - no hint at all at 40x11, half a hint at 40x12 #1027

Found while sweeping the fifth "no half blocks" case (#1012 → #1014, #1015 → #1026). Different block, same payer: the
confirmation dialog.

draw() sizes the modal box to its body and clamps it to the frame (bh = (body.len() + 2).min(area.height)), then
draws the body with Paragraph, so when the body does not fit, ratatui clips its end - and the last line of every
dialog is the hint, the only row that says how to answer.

Measured on the shipped static binary (main 434db3d2's build, 0edbe573…), real ptys, TERM=linux, key 1 on a
blank-key box (API key / Require one from now on? … / y mints one and restarts Lemonade, n cancels):

The same clamp applies to every dialog, and the text is worse for the destructive ones: Modal::Confirm { yes: Yes::Reboot } carries y reboots the box, n cancels, and Modal::Power carries r reboots, p powers off, any other key cancels. So in a 40x11 ssh window the screen shows the question and no visible way to answer it, while y still
does what the question says. Not reachable from the gates (80x25 / 240x67 have the rows), so no gate impact - but it
is the one place where a key the screen does not explain changes the box.

The fix belongs to the same family as #1014/#1015: the hint is the block's last row but the most load-bearing, so a
frame too short for the whole box should lose the question rows first (whole rows at a time), then the title, and
never the hint. PR follows.