Without a sync-ready gate, a transient GET failure during autoConnectAll
left the local registry Map empty/incomplete while `set()` still computed
`registryUpdatedAt = Date.now()`. The trailing `syncRegistry()` would then
PUT the empty payload with a fresh timestamp; the server's LWW guard
accepted it and legitimate registry rows were wiped — including
remote-instance entries the user never explicitly removed.
Add `_registrySyncReady` flag, set true only after a successful initial
GET. `syncRegistry()` short-circuits while false, so the degraded mode
(GET failed) is display-only: the Map is still populated locally from
\`replicatedInstances\` synthesis (status \`auth_expired\`) so the
Connections UI shows the user's known remotes, but mutations don't push.
On the next session where GET succeeds, localStorage cached tokens
reseed the registry and \`syncRegistry()\` pushes the merged authoritative
state — no data lost, sync deferred until we have a complete picture.
\`reset()\` clears the flag alongside the registry. Spec updated with the
sync-ready gate and degraded-mode behavior. Unit tests cover the gate
on initial fail, mutations during degraded mode, recovery on next
successful GET, and the synthesis fallback for empty replicatedInstances.
Jannis Braun
06498836bb