Keep two shot rows visible in Authoring on shorter windows

The step headings make the panel taller, so the left stack squeezed the
shot list down to one row at about 1000px of window height. Its minimum
now holds two rows; the panel scrolls when space is short.

src/ui/styles/scenes.css

@@ -245,7 +245,8 @@ html:not([lang='en']) #scene-panel .scene-controls .scene-btn {
   flex-direction: column;
   gap: 6px;
   max-height: 260px;
-  min-height: 72px;
+  /* Two shot rows stay visible; the panel scrolls when space is short. */
+  min-height: 128px;
   flex: 1;
   overflow-y: auto;
   padding: 4px 2px 6px;