- T-4: every ReadAsync batch fetched and parsed the whole device /current and
built a fresh index even while the /sample pump held a live one. A read is now
answered from the pump's index (read only - the pump stays its single writer)
while the current-generation pump is running, has delivered since it started and
is not degraded; /current stays the fallback, and its per-batch index is built
over a tag map frozen once per binding instead of per call. A served read clears
the read-path degradation a failed /current left.
- T-2: the /current fallback checks the answer's instanceId; a change (an Agent
restart seen by a browse-only driver) drops the cached /probe model and raises
rediscovery once per distinct id, only while the read's session is still installed.
- The pump also acts on no verdict (Degrade / latch) once its session generation
is gone, so an abandoned pump cannot write health over the new session (T-1 follow-through).
Refs #743
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
Joseph Doherty