[Timeline] Fix #212 by re-applying animation state on scene load

[Lusiocc]

Description

SceneLoad only re-applied animation state when Autoplay was Yes or No. The default is Ignore, which did neither, and InterpolateBefore/InterpolateAfter early-return while paused. So after a load the cursor and the scene sat on different frames. Added the missing branch: re-apply at the current playback time without touching play state.

Motivation and Context

Fixes #212. Auto Keyframe's "Auto current value" rewrites the keyframe under the cursor from live scene state, so the desync silently destroyed the keyframe at 0:00. The desync itself is reproducible with Auto Keyframe uninstalled.

How Has This Been Tested?

KK, Timeline 1.5.5.1 + Auto Keyframe 1.3.0.0.
Against main, confirming the bug:

• Cursor/scene desync after load, with Auto Keyframe uninstalled
• Keyframe at 0:00 overwritten with the card's pose
• Overwrite follows the cursor, not keyframe 0, parked at 0:05, that keyframe was hit instead
• Nothing overwritten with the cursor parked between keyframes, despite the desync
• No overwrite for a card saved at 0:00
• No overwrite when loaded during playback
• No overwrite with Autoplay = No

Against the fix:

• Scene matches the cursor immediately on load, no desync
• No keyframe modified in any of the repro cases

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

[HanYuanyi]

Thank you