feature: smooth moving camera

[quanghuynh99]

Description & motivation

Summary

• Improves the render timing pipeline in Screen.swift to reduce frame stutter/freezing during fast camera movement.

• Stabilizes frame pacing and timestamps before creating CMSampleBuffer .
  Root Cause

• presentationTimeStamp could become non-monotonic when capture/render latency fluctuates.

• frameDuration could vary too much between consecutive frames during rapid motion.

• Sudden latency shifts caused visible jitter and short frame stalls.

Type of change

Please delete options that are not relevant.

• Introduced ScreenTimingSettings with normalized timing bounds.
• Clamped frameDuration to min/max limits for stable frame pacing.
• Enforced strictly monotonic presentationTimeStamp using minimumMonotonicStep .
• Smoothed capture latency with EMA ( videoCaptureLatencySmoothingFactor ) and capped it ( maximumVideoCaptureLatency ).
• Preserved renderer state (bounds/background/sync clock) when renderer configuration changes.

Demo (video from Android using VLC app that watch video stream from iPhone X):

https://drive.google.com/file/d/186ImpDCjmSb8kGZUJe70n8F7CpUqfKOw/view?usp=sharing