Reduce duplicate network reads for 3D Blu-ray playback
The 3D video reader and audio player can read overlapping base-view data from the same disc over SMB, increasing bandwidth demand. RAR-backed discs also need to benefit from parallel network reads.
Shared base-stream caching and pooled reads for RAR volumes are implemented in development builds. End-to-end playback validation is still in progress. These changes are not yet included in public Store version 0.12.11, and improved full-film reliability is not yet confirmed.
