0.4.0

• Default to native sample-buffer playback on all platforms, with Metal selected for custom rendering and advanced features.
• Release native playback resources on stop while preserving the source and settings for replay.
• Preserve rendering commands across backend reloads and runtime settings across stop and replay.
• Reduce redundant metadata updates and report decoder-session changes promptly.
• Add demuxer cache totals and engine activity diagnostics.
• Add physical-device playback benchmarks and expand rendering, seeking, and lifecycle tests.