feat(studio): always-on crop with reposition handle, drop crop mode (#2090)

Crop is now part of the element selection instead of a separate mode. Selecting
a croppable element shows edge handles just outside each side and, once cropped,
the full content with the cropped-away area dimmed plus a center reposition
handle to pan the crop window. Dragging the body moves the element, edge handles
crop, the center handle pans; corners stay free for the resize handle. Removes
the crop-mode toggle (toolbar + property-panel buttons), the cropMode/
cropAvailable player-store state, and the double-click-to-crop gesture. The
clip-path inset model is unchanged.

packages/studio/src/player/components/ShortcutsPanel.tsx

@@ -63,10 +63,8 @@ const SHORTCUT_SECTIONS = [
   {
     title: "Crop",
     hints: [
-      { key: "DblClick", label: "Crop selected element" },
-      { key: "Drag edge", label: "Adjust crop side" },
-      { key: "Drag frame", label: "Move crop window" },
-      { key: "Esc", label: "Exit crop (or click outside)" },
+      { key: "Drag edge", label: "Crop a side" },
+      { key: "Drag center", label: "Reposition the crop" },
     ],
   },
   {