cap the scale at 2x

The quarter steps did not actually shrink it. In a panel around 1500x950
device pixels the fit is 2.56, and floor(2.56 x 4) / 4 is still 2.5 — the finer
steps changed where the next size would land, not this one.

So a ceiling instead of another nudge: 2x, whatever room the panel has. That is
a taste decision rather than a limit of the method — past 2x this stops reading
as a window on a desktop — and the panel header has a zoom control, so it is a
default, not a verdict. Raise MAX_SCALE and the quarter steps take over again.

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

README.md

@@ -96,6 +96,10 @@ exactly 36 screen pixels, as even as at 2x, and only sub-cell pixels alternate.
 than halves because coarse steps overshoot — with halves this jumped 2x to 2.5x, too small to too large
 with nothing in between.
 
+The scale is then 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. That is a default, not a verdict — the panel header has a zoom control,
+and `MAX_SCALE` is one constant.
+
 Two things the scale has to know about that are easy to miss. `devicePixelRatio` is not the whole story:
 the panel header has its own CSS `zoom`, so the effective ratio is `devicePixelRatio × zoom`, read as
 `getBoundingClientRect().width / offsetWidth`. And the stage is fitted into the box MINUS a margin, because

web/MinesweeperPanel.tsx

@@ -27,6 +27,17 @@ const BUTTON_MASK: Record<number, number> = { 0: 1, 1: 2, 2: 4 };
 /** Breathing room around the stage, in device pixels. Small — it is a frame, not a margin. */
 const MARGIN_DEVICE_PX = 24;
 
+/**
+ * The ceiling on how large the game is drawn, whatever room the panel has.
+ *
+ * A taste decision, not a limit of the method: fitting the panel is not the same as looking right, and
+ * past 2x this stops reading as a window on a desktop and starts reading as a wall. Raise it and the
+ * quarter steps below take over again.
+ *
+ * The panel header has a zoom control, so this is a default rather than a verdict.
+ */
+const MAX_SCALE = 2;
+
 // Plugin panels have no localisation mechanism yet — `officerdev`'s `useTranslation`/`panelCatalogs`
 // (merged by `I18nBridge`) is platform-internal and not exported from the barrel, and
 // `scripts/i18n/scan-hardcoded.ts` explicitly does not scan `plugins/`. So these stay plain English
@@ -124,7 +135,8 @@ export const MinesweeperPanel = () => {
     const fit = Math.min(usableW / frame.width, usableH / frame.height);
     // Below 1 there is nothing to floor to, so take a unit fraction: the rows that survive are then
     // evenly spaced instead of dropped in clumps.
-    const scale = fit < 1 ? 1 / Math.ceil(1 / fit) : fit < 2 ? 1 : Math.floor(fit * 4) / 4;
+    const snapped = fit < 1 ? 1 / Math.ceil(1 / fit) : fit < 2 ? 1 : Math.floor(fit * 4) / 4;
+    const scale = Math.min(snapped, MAX_SCALE);
     return { width: (frame.width * scale) / box.dpr, height: (frame.height * scale) / box.dpr };
   }, [frame, box]);