A node whose database was briefly away recovers by itself

When a node's hub started up during a short database or DNS outage, its initialisation failed and the hub was marked failed for good: every later request to that node was refused with "initialization failed", the node rendered as unavailable, and only a recycle or a portal restart brought it back — long after the database had returned.

A start-up that fails on a transient infrastructure fault now retires that activation instead of marking it failed. Anyone waiting on it is told the address is shutting down and may be retried, the hub disposes itself, and the next request creates it afresh, so its initialisation runs again against the database that has meanwhile come back. Faults that really belong to the node — a type that does not compile, a handler that throws — are still reported as before, and a hub that cannot be re-created on demand (the portal's root hub, a stream's own sub-hub) keeps the previous behaviour with a log line that now names the transient cause.