Reproduction case for many clips freezing issue

[remorses]

Description

This PR provides a minimal reproduction case for the issue where having many clips (more than 30) in a composition causes the player to freeze during playback.

Changes

• Modified the playground example to create 40 video clips with 3-second duration each
• Removed all non-essential layers and effects to isolate the issue
• Uses a sliding window approach to create overlapping clips from a single video source

How to Reproduce

1. Run the playground with this branch
2. Start playback
3. The player will freeze after approximately 4 seconds

Related Issue

This reproduction case demonstrates the issue described in #86

Notes

The freeze happens consistently when there are many clips in the composition, regardless of the video duration. The timing of the freeze is inversely related to the number of clips - more clips cause the freeze to occur sooner.