59d33ab938
Adds an escalated-stream-fault test seam and a test: the live pump's fault escalates (positive controls before and after), a superseded pump's late fault after a reopen does not; the absence is asserted only once both pumps' callbacks are known to have run (HasEnded). Verified to fail with the filter disabled. The filter's comment now says the identity check does the work and warns about a future session bump while Healthy. Claude-Session: https://claude.ai/code/session_01GT67AD99zQQqpLCVm3p7xk