The user confirmed successful empty-Enter and soak testing, closing 8D.4 while leaving numeric reserve gates open and advancing the next planned work to 8D.5.
Implement transport-qualified session identity and immutable owner adapters for SSH console lifecycle and output-drain operations. Add focused host tests covering admission, stale identities, deferred actions, completion races, prompts, backpressure, and slot reuse. Update Phase 8D documentation and current-state tracking.