stage 512x384, so a replay can open

"Your screen cannot fit a window of that size" on Extras > Play Recording.
The replay window is 504x342 — exactly expert, which the 512x352 stage holds
with ten pixels to spare — so the message is not about the window it is about
to draw.

Not a positional check either, which was the first guess: from a centred
beginner window an expert window would run 236px off the right edge, and the
game repositions it without complaint. It is a minimum-screen check wanting
slack it never spends, roughly the title bar it does not have here.

Measured rather than reasoned about, on a stage enlarged for the purpose: the
replay window is 504x342, the file dialog 420x239. Then 512x352 verified
refusing a replay and 512x384 verified opening one.

The height is the whole fix; the width is unchanged. That matters because 42
more pixels of stage cost nothing at the sizes people use: the panel caps the
scale at 2x, so any stage up to about 726x451 draws the game at exactly the
same size. The stage only starts costing pixels once the fit falls under the
cap — which is also why the number is generous rather than the minimum that
passes.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Officer-Session: de3ed4e6-f88a-429c-94e6-a760336ba83b

README.md

@@ -82,7 +82,7 @@ The check that matters is `ss -lntp` against the **running** process. Reading th
 listener that exists because a flag is missing, and running the same arguments by hand did not reproduce
 it either.
 
-**The game is centred on a fixed stage, and the whole stage is what you see.** The framebuffer is 512x352
+**The game is centred on a fixed stage, and the whole stage is what you see.** The framebuffer is 512x384
 whatever the difficulty, `sidecar/session.ts` keeps the window in the middle of it, and the panel draws the
 framebuffer entire — scaled to fit, never cropped. So changing difficulty moves the board rather than
 resizing the panel, and the surround is teal (`-solid`) rather than the root's black.
@@ -96,6 +96,11 @@ stay regular is the CELL: the board is a 16px grid, so every quarter step gives
 overshoot, and quarters all the way down rather than whole numbers under 2x because otherwise zooming out
 from a 2x baseline falls straight to 1x and halves the board in one press.
 
+The stage is 512x384 rather than 512x352 because the game refuses to open a REPLAY on a screen only ten
+pixels taller than the board — "Your screen cannot fit a window of that size", for a window it is about to
+draw at exactly 504x342. It wants slack it never spends. Growing the stage is free at the sizes people use:
+the scale is capped at 2x, so anything up to about 726x451 draws the game identically.
+
 The BASELINE — the size at 100% — is capped at 2x. Fitting the panel is not the same as looking right, and
 past 2x this stops reading as a window on a desktop.