fix(studio): prevent negative timeline latency telemetry

[miguel-heygen]

What

• Measure scroll-to-next-frame callback latency with performance.now() at both ends.
• Add a hook-level regression for an animation-frame timestamp that predates the scroll handler.

Why

The animation-frame callback timestamp can represent the current frame and be earlier than performance.now() captured by a scroll handler. Subtracting those two clocks produced impossible negative latency samples.

How

Keep the animation-frame timestamp for frame-to-frame cadence, but use the monotonic performance.now() clock for both the scroll start and callback delivery time.

Test plan

• Focused telemetry hook regression
• Studio TypeScript check
• Full Studio test suite (3,124 tests)
• Changed-file lint and formatting
• Manual testing performed
• Documentation updated (not applicable)