- oakengine_renderer_create/set_mode/last_error, render_frame (sync,
60s timeout, CPU frames via the existing worker pool),
render_audio (planar float), cancel; frames and audio buffers are
owned handles with borrowed data pointers
- output colorspace names map to OCIO display transforms, with
graceful fallback to reference-space output
- oakengine_renderer_test: parameter validation and error paths need
no GL and always run; render assertions gate on
DynamicRenderer backend availability and SKIP cleanly otherwise
- fix a facade bug found by its own test: wait_for_ticket leaked a
connected lambda capturing a stack reference, which a subsequent
cancelled ticket could fire into reused stack memory
