* fix(server): retry a connected host that failed the capability check
Every failure in a connected host's acceptance step was terminal: the
row went to "error" with no retry, and the status listener ignored
later reconnects. A host rejected with unsupported_capability stayed
unusable after it was updated, until the registration was saved again
or the managing daemon restarted. Capability and other non-identity
acceptance failures now go "offline" with nextRetryAt and retry with
capped backoff (1.5 s doubling to 30 s), so an updated host comes
online by itself. Self, duplicate, changed-identity and authentication
failures stay terminal.
Fixes#7971
* fix(server): keep a retried host's relay security floor and update guidance
A scheduled capability retry built a new transport factory, which
dropped the relay security floor learned from a protected handshake, so
the retry could negotiate legacy encryption and send credentials.
Retries now reuse the registration's transport factory (createHostClient
accepts one). The update guidance also stays visible while a retry
connects, the backoff resets after a successful acceptance, and
disabling or removing a host cancels its pending retry.
Dominic
9b0542d127