Simplified Audio Timestamps, Pause/Resume Fixes & Preset Management - Cap

Simplified audio timestamp generation — Replaced complex drift tracking with sample-based timestamp generation for more reliable and predictable audio timing. This eliminates edge cases with clock drift detection and produces cleaner, more accurate audio synchronization.
Improved pause/resume handling — Added shared wall clock pause tracking that correctly accounts for paused time in both video and audio pipelines. Recordings now seamlessly continue with accurate timestamps after pausing and resuming.
Better frame recovery during playback — Increased fallback distance for frame cache lookups, especially near the end of videos. Playback now handles missing frames more gracefully by using nearby cached frames rather than failing.
Preset management improvements — Added ability to clear all presets and improved configuration default handling. Default cursor mode now uses raw positioning for snappier cursor movement.