The resolved-identity match in canonical auto-register always preserved
the stored host, so the route-aware IP preference added to the agent in
022f170df could never take effect for an already-registered node: a
reinstall re-matched the node and kept the stale short-DNS host forever.
Preserve the stored host only when it is absent from the agent's ordered
candidate list (an admin-managed endpoint the agent cannot see); when the
agent itself lists the stored host as a lower-priority candidate, adopt
the newly selected host. Identity continuity (same node record, same
token) is unchanged.
Note: commit c21693489 carries this same message by mistake; it actually
contains concurrent OIDC/SAML mapping work from a parallel session that
was staged when the shared index raced. This commit is the real change.
rcourtman
f850099134