Use persistent privacy-filtered capture targets and client-owned GPU buffers with fence completion, backpressure, negotiated frame rates and shared-memory fallback.
Invalidate output views on scene changes while preserving inactive-window callbacks and capture revocation. Include OBS memory-mask negotiation and native pixel, transport and recording regressions.
Render selected toplevels through a private portal-only capture protocol, preserve logical snapshot geometry, and renegotiate PipeWire video on window resizing. Bound outstanding snapshots and retry temporary contention; stop on source closure and session locking.
Validation: portal unit tests (31), capture budget unit, private-bus portal contracts, and real nested/PipeWire isolation, workspace, resize, close and paused-lock tests pass. Independent review cleared. Monitor restore integration timed out on both this build and the unchanged previous compositor under the current nested host.
Samuel Onoja