Real-env console (2026-06-15) showed the breaker never opening even as
decrypts failed for minutes. Cause: the breaker treated every non-timeout
error as "channel alive" and RESET the timeout streak — but
"message channel closed before a response was received" is the exact
dead-channel signal, and it rejects as a (fast) non-timeout error. So each
such rejection reset the counter and the circuit could never open.
Classify channel-death messages (message channel closed / could not
establish connection / receiving end does not exist / extension context
invalidated / connection lost) as channel failures that count TOWARD
opening the circuit, instead of as responsive failures that reset it.
Genuine extension responses (user rejection, permission denied, etc.)
still reset the streak.
Test: extends nip07-channel-breaker with a synchronous channel-closed op
asserting consecutive channel-death errors open the circuit and then
fast-fail (no waits).
Co-Authored-By: Claude Opus 4.8 <[email protected]>
