Slides and Video Layout Fixes, Consistent Crop Handling

✨ New Features

• Added max height limits for slides and video so nothing gets clipped on screen.
• Video demo

🛠 Fixes

• Fixed: dragged slides now use the same cropped image as “Add to Branch”, so what you see is exactly what gets added.
• Fixed: crop bounds stay correct when resizing the window, no more jumping or stretched crops.

And other improvements