fix(storybook): refine responsive page inner width

- Story page Inner side margin: 16px up to a 480px viewport, linear to 60px at 768px, 60px beyond (no width jump)
- Follow the 60px margins: Responsive 1920 row from a 2040px page (was 2000px); property compare 3 columns from 1125px, 2 columns from 787px (was 1080 / 720)
- SW browser tests: drop the removed --sb-page-max-width override, compare thresholds 787 / 1125

packages/sw/tests/property-panel-comparison.browser.mjs

@@ -91,7 +91,9 @@ try {
       report.data[`gaps${width}`] = { colGap, colGap2, rowGap }
       // 2026-10-22 (user request): no Inner scroller; the page scrolls. 2 columns × 2 rows, one column below 720px.
       // 2026-10-26 (user request): from 1080px, 3 columns — none/all stacked in column 1, circle and expanded beside them.
-      const oneColumn = width < 720, threeColumns = width >= 1080
+      // 2026-11-05: the Story page Inner keeps 60px on each side (story-page.css), so the steps moved to 787px / 1125px
+      // (sw-stories.css .sw-story-compare--grid). It keeps 16px up to 480px (growing to 60px at 768px), so 390px has 358px.
+      const oneColumn = width < 787, threeColumns = width >= 1125
       if (threeColumns) {
         const gaps = { stack: b.cell.y - a.cell.bottom, col1: c.cell.x - Math.max(a.cell.right, b.cell.right), col2: d.cell.x - c.cell.right }
         report.data[`gaps${width}`] = gaps