Phase 6.2 Stream A — LdapGroupRoleMapping entity + EF migration + CRUD service

Stream A.1-A.2 per docs/v2/implementation/phase-6-2-authorization-runtime.md.
Seed-data migration (A.3) is a separate follow-up once production LDAP group
DNs are finalised; until then CRUD via the Admin UI handles the fleet set up.

Configuration:
- New AdminRole enum {ConfigViewer, ConfigEditor, FleetAdmin} — string-stored.
- New LdapGroupRoleMapping entity with Id (surrogate PK), LdapGroup (512 chars),
  Role (AdminRole enum), ClusterId (nullable, FK to ServerCluster), IsSystemWide,
  CreatedAtUtc, Notes.
- EF config: UX_LdapGroupRoleMapping_Group_Cluster unique index on
  (LdapGroup, ClusterId) + IX_LdapGroupRoleMapping_Group hot-path index on
  LdapGroup for sign-in lookups. Cluster FK cascades on cluster delete.
- Migration 20260419_..._AddLdapGroupRoleMapping generated via `dotnet ef`.

Configuration.Services:
- ILdapGroupRoleMappingService — CRUD surface. Declared as control-plane only
  per decision #150; the OPC UA data-path evaluator must NOT depend on this
  interface (Phase 6.2 compliance check on control/data-plane separation).
  GetByGroupsAsync is the hot-path sign-in lookup.
- LdapGroupRoleMappingService (EF Core impl) enforces the write-time invariant
  "exactly one of (ClusterId populated, IsSystemWide=true)" and surfaces
  InvalidLdapGroupRoleMappingException on violation. Create auto-populates Id
  + CreatedAtUtc when omitted.

Tests (9 new, all pass) in Configuration.Tests:
- Create sets Id + CreatedAtUtc.
- Create rejects empty LdapGroup.
- Create rejects IsSystemWide=true with populated ClusterId.
- Create rejects IsSystemWide=false with null ClusterId.
- GetByGroupsAsync returns matching rows only.
- GetByGroupsAsync with empty input returns empty (no full-table scan).
- ListAllAsync orders by group then cluster.
- Delete removes the target row.
- Delete of unknown id is a no-op.

Microsoft.EntityFrameworkCore.InMemory 10.0.0 added to Configuration.Tests for
the service-level tests (schema-compliance tests still use the live SQL
fixture).

SchemaComplianceTests updated to expect the new LdapGroupRoleMapping table.

Full solution dotnet test: 1051 passing (baseline 906, Phase 6.1 shipped at
1042, Phase 6.2 Stream A adds 9 = 1051). Pre-existing Client.CLI Subscribe
flake unchanged.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/ZB.MOM.WW.OtOpcUa.Configuration/Enums/AdminRole.cs

@@ -0,0 +1,26 @@
+namespace ZB.MOM.WW.OtOpcUa.Configuration.Enums;
+
+/// <summary>
+///     Admin UI roles per <c>admin-ui.md</c> §"Admin Roles" and Phase 6.2 Stream A.
+///     These govern Admin UI capabilities (cluster CRUD, draft → publish, fleet-wide admin
+///     actions) — they do NOT govern OPC UA data-path authorization, which reads
+///     <see cref="Entities.NodeAcl"/> joined against LDAP group memberships directly.
+/// </summary>
+/// <remarks>
+///     Per <c>docs/v2/plan.md</c> decision #150 the two concerns share zero runtime code path:
+///     the control plane (Admin UI) consumes <see cref="Entities.LdapGroupRoleMapping"/>; the
+///     data plane consumes <see cref="Entities.NodeAcl"/> rows directly. Having them in one
+///     table would collapse the distinction + let a user inherit tag permissions via their
+///     admin-role claim path.
+/// </remarks>
+public enum AdminRole
+{
+    /// <summary>Read-only Admin UI access — can view cluster state, drafts, publish history.</summary>
+    ConfigViewer,
+
+    /// <summary>Can author drafts + submit for publish.</summary>
+    ConfigEditor,
+
+    /// <summary>Full Admin UI privileges including publish + fleet-admin actions.</summary>
+    FleetAdmin,
+}