v2.16.1-dev.0 — card-picker preview + drag-preview improvements

Dev pre-release for local-HA verification before promoting to stable v2.16.1.

Added

• Live preview in the HA Community card picker (was a blank tile).
• Drag a single light's curve point to live-preview just that light.

Fixed

• Dragging the floor/origin point previews the dimmed level instead of turning the light off.