fix: resolve loot/roll frame animation jumping

[Xerrion]

Summary

Fixes the loot and roll frames visually "jumping" during open/close animations. Two root causes addressed:

1. LibAnimate forced scale=1.0 on every animation tick, overriding user-configured frame scale
2. Animation interruption (close during open) snapped the frame to its pre-animation state before starting the close animation

Changes

Updated embedded LibAnimate

Synced from Xerrion/LibAnimate#58 - animations now only touch properties they define. Scale is relative to originalScale.

LootAnimations.lua

• Capture/restore visual state on animation interruption so close animation starts seamlessly from where the frame visually was
• RestoreDbAnchor in close onFinished resets position for next open (important for slide animations)
• isClosing flag to prevent layout changes during close animation
• Fixed StopAll ordering (before SetAlpha(0), not after)

RollAnimations.lua

• Same capture/restore pattern applied for roll frame animations
• isClosing flag exported via ns.RollAnimations.isClosing

LootFrame.lua

• UpdateSlot guards LayoutSlots() with isClosing check to prevent mid-close-animation resizing

Testing

1. Set loot window scale to something other than 1.0 in config
2. /dl test - frame should open at correct scale throughout animation (no jump)
3. Close - should fade out at correct scale (no snap to 1.0)
4. Rapid open/close (loot a mob and walk away) - smooth, no flash
5. /dl testroll - roll frames animate without scale jumping