Improved HDR Support and Color Management

OpenRV is expanding its HDR and color management capabilities to better support modern production and review pipelines. Improvements include updated OCIO workflows, more consistent color handling across platforms and displays, and enhanced support for HDR monitoring and playback.

The issue names OCIO workflows, cross-platform color handling, and HDR monitoring and playback, but provides no files, tests, or entry points. Start by locating those existing workflows and playback paths, then establish platform and display acceptance criteria; the work is done when the stated HDR and color-management improvements behave consistently across supported environments.

Written by the indexing model from the issue text.