Timeline & Templates Polish

April focused on deepening the animation and template systems. The SelectionManager was extracted as a dedicated module to manage drag targets cleanly across panels. Width and height input fields landed in the Transform Inspector, giving numeric control over asset dimensions. The Hierarchy panel gained drill-down navigation — double-clicking a container zooms you into it. Timeline got lock/unlock per layer and frame-management buttons. Duplicate template was added from the Properties panel. The first robot template assets appeared as bundled examples. The easing system was extended with an "Apply to All" button on the timeline, and the Copy/Paste Properties feature let you copy transform values between assets.