v0.2.0

• Interactive Panel preview: the preview now mirrors the frontend
  (overlaid images with a divider) and dragging the divider writes the
  released position back into the block's start field — the range field
  in the drawer stays in sync. Double-clicking the preview opens the drawer.
• The Panel preview uses the before image's aspect ratio (like the
  frontend), capped at a maximum height, instead of a flat fixed-height
  strip.
• The handle arrows now scale with the grip (75 % of
  --image-compare-handle-size) and are tunable via the new
  --image-compare-arrow-size custom property.