Keep one queued and one replaceable pending snapshot for remote-library and Call-to-Play views while preserving lifecycle-event FIFO delivery. Generation barriers and fenced drains prevent stale nonempty views from crossing disable or acknowledgement boundaries.
Test Plan:
- just test
- just clippy
- focused burst, lifecycle ordering, fence, repeated-barrier, and stale-view tests
- independent ordering review
- git diff --check
ddidderr
37420e26ed