A JetStream 503 or a timeout at the follow (a bus right after its boot) left the module with no membership for good, since
Follow runs once per module and the stream fallback is gone. The read is now tried again with a growing wait (1 s doubling
to 30 s) until it watches the key or the connection closes; the failure is said once, and its reading once it succeeds.
Tests: none added; a step added to an existing unit test (TestAModuleHearsEveryStreamItsMembershipNames), which fails
without the retry.
(issue 774, 774/S32, review g1 round 1)
Claude-Session: https://claude.ai/code/session_01NcbgfJ9Gum47zkFKWRaovL