feat(security): enforce node ACLs on write, alarms and HistoryRead (#520 stage 5)

`Security:Acl:Enabled` (default false) makes scoped `NodeAcl` grants decide
data-plane authorization at the three seams that have one, and gives HistoryRead
a check it never had. Read, Browse and Subscribe stay ungated — stage 6.

The ACL decision REPLACES the server-wide role check rather than chaining with
it. Chained, a grant would have to confer the role as well as pass the scope
check, and only Cluster-scoped grants confer a role — so every narrow grant
would have stayed inert and the flag would have looked inert too. The
load-bearing test is an ALLOW: a session carrying no roles at all writing
successfully on the strength of its grant. A deny-only test passes against a
build where the ACL is never consulted, because the role gate denies too.

Found en route: the principal never reached the session. The authenticator
passed it as OpcUaUserAuthResult.DisplayName, but RoleCarryingUserIdentity
derives DisplayName from the presented token — for a key-bearing client that is
the static username `apikey`, identical fleet-wide. So the trie's matching key
was dropped at the identity boundary, and the audit ClientUserId on a rejected
write recorded `apikey` for every consuming system. Principal and ApiKeyId are
now carried explicitly.

Beyond the stage as sketched:

- Revocation reaches an OPEN session. Every decision re-checks the
  authenticating key against the current snapshot; without it a key revoked by a
  deployment kept its authority until the client chose to reconnect, which for a
  machine-to-machine consumer can be indefinitely.
- UserAuthorizationState is built per CALL, not per session. The per-session
  shape exists so an LDAP session can re-resolve membership that changed out of
  band; nothing can change out of band under API keys, so the generation stamp is
  the whole invalidation signal and a per-call record picks it up for free.
  IsStale/NeedsRefresh therefore cannot fire here and are documented as vestigial.
- The trie is built inside DataPlaneAuthorityState.Apply, under the same
  generation as the snapshot, rather than by a second wiring at the publish
  actor. An uninstalled trie denies everything — indistinguishable from working
  enforcement. Deleting the install turns 13 of the 22 new tests red.
- The deploy log reports what the BUILD dropped instead of re-deriving it. The
  old count agreed with the builder on one of its four drop reasons; a rule with
  a blank ScopeId, a retired scope kind, or a path not starting at a realm
  vanished with the log reading zero.

Both IApiKeyStore implementations widened to the full grant set. The narrowing
was redundant — ApiKeyInterimRoleMapper applies the same filter itself — and
became a trap once scope was enforced. Pinned by asserting the roles are
unchanged, with the two grants carrying different flags so it cannot pass by
accident.

Falsified by mutation: enforcement never engaging, the write seam ignoring the
ACL, the realm dropped from the scope, the revocation check removed, and the
trie never installed each turn the intended tests red and no others.

Full solution suite green.

Claude-Session: https://claude.ai/code/session_015p7wGqy3YpZNCpDzTpGMKo

src/Server/ZB.MOM.WW.OtOpcUa.Runtime/OpcUa/OpcUaPublishActor.cs

@@ -536,26 +536,33 @@ public sealed class OpcUaPublishActor : ReceiveActor, IWithTimers
             var snapshot = _dataPlaneAuthority.Apply(
                 projection.ClusterId, revision, projection.Keys, projection.Grants, projection.ScopePaths);
 
-            // unresolvedScopes counts grants narrower than Cluster whose ScopeId named nothing in this
-            // artifact — a dangling id, or a scope kind with no v3 entity behind it. Those grants will be
-            // dropped when the trie is built, so surfacing the count here is the operator's only warning
-            // that a rule they authored is not going to do anything.
-            var unresolvedScopes = projection.Grants
-                .Where(g => g.ScopeKind != NodeAclScopeKind.Cluster && !string.IsNullOrEmpty(g.ScopeId))
-                .Select(g => new AclScopeRef(g.ScopeKind, g.ScopeId!))
-                .Distinct()
-                .Count(r => !projection.ScopePaths.ContainsKey(r));
-
             _log.Info(
                 "OpcUaPublish: data-plane authority generation {Generation} installed (cluster={Cluster}, revision={Revision}, keys={Keys}, grants={Grants}, resolvedScopes={ResolvedScopes})",
                 snapshot.GenerationId, projection.ClusterId ?? "(single-cluster)", revision[..12],
                 projection.Keys.Count, projection.Grants.Count, projection.ScopePaths.Count);
 
-            if (unresolvedScopes > 0)
+            // Reported BY the trie build (#520 stage 5), not re-derived here. The previous version of this
+            // log counted unresolvable ScopeIds itself and so agreed with the builder on exactly one of its
+            // four drop reasons — a row with a blank ScopeId, a retired scope kind, or a scope path that
+            // does not start at a realm all vanished with the log still reading zero. A dropped row is an
+            // authored rule that can never match, and this is the operator's only warning of it.
+            if (snapshot.DroppedGrants.Count > 0)
             {
                 _log.Warning(
-                    "OpcUaPublish: {Unresolved} ACL scope(s) in generation {Generation} name nothing in the deployed address space — grants on them will be DROPPED, not applied. Check the ScopeId on those rules",
-                    unresolvedScopes, snapshot.GenerationId);
+                    "OpcUaPublish: {Dropped} ACL rule(s) in generation {Generation} were DROPPED and will never match — {Detail}",
+                    snapshot.DroppedGrants.Count, snapshot.GenerationId,
+                    string.Join("; ", snapshot.DroppedGrants
+                        .Select(d => $"acl {d.NodeAclId} ({d.ScopeKind} '{d.ScopeId}') {d.Reason}")));
+            }
+
+            if (string.IsNullOrWhiteSpace(projection.ClusterId) && projection.Grants.Count > 0)
+            {
+                // No cluster identity means no trie was built at all, so nothing can be granted here. Say
+                // so explicitly: with enforcement on, this node denies every write, alarm command and
+                // HistoryRead, and the grant count logged above would otherwise suggest the opposite.
+                _log.Warning(
+                    "OpcUaPublish: this node has no cluster identity, so NO permission trie was built for its {Grants} grant(s) — with Security:Acl:Enabled every scoped decision here will be denied",
+                    projection.Grants.Count);
             }
         }
         catch (Exception ex)