Step 6

docs/PHASE_7_BACKEND_LIFECYCLE_PLAYOUT_DESIGN.md

@@ -4,6 +4,8 @@ This document expands Phase 7 of [ARCHITECTURE_RESILIENCE_REVIEW.md](/c:/Users/A
 
 Phase 4 made the render thread the sole owner of normal runtime GL work, but output timing is still callback-coupled: DeckLink completion callbacks synchronously request render-thread output production before scheduling the next hardware frame. Phase 7 should make backend lifecycle, buffer policy, playout headroom, and recovery explicit.
 
+Phase 5 clarified that live parameter layering stops at final render-state composition. Phase 7 should keep backend lifecycle, output queue ownership, buffer reuse, temporal/feedback resources, and stale-frame/underrun policy outside the persisted/committed/transient parameter model.
+
 ## Status
 
 - Phase 7 design package: proposed.
@@ -49,6 +51,7 @@ Phase 7 should not require:
 
 - a new renderer
 - changing shader/state composition
+- changing committed-live or transient automation layering
 - replacing DeckLink support with multiple backends
 - full telemetry UI redesign
 - removing every synchronous API immediately
@@ -73,6 +76,8 @@ The callback should not wait for rendering. It should:
 - schedule the next frame
 - publish backend timing/health observations
 
+The queue contains rendered output-frame ownership and scheduling metadata, not live parameter state. Parameter composition should already be resolved before an output frame enters this playout boundary.
+
 ## Target Lifecycle Model
 
 Suggested backend states: