Phase 2 — port GalaxyRepository to Galaxy.Host + DbBackedGalaxyBackend, smoke-tested against live ZB. Real Galaxy gobject hierarchy + dynamic attributes now flow through the IPC contract end-to-end without any MXAccess code involvement, so the OPC UA address-space build (Stream C.4 acceptance) becomes parity-testable today even before the COM client port lands. Backend/Galaxy/GalaxyRepository.cs is a byte-for-byte port of v1 GalaxyRepositoryService's HierarchySql + AttributesSql (the two SQL bodies, both ~50 lines of recursive CTE template-chain + deployed_package_chain logic, are identical to v1 so the row set is verifiably the same — extended-attributes + scope-filter queries from v1 are intentionally not ported yet, they're refinements not on the Phase 2 critical path); plus TestConnectionAsync (SELECT 1) and GetLastDeployTimeAsync (SELECT time_of_last_deploy FROM galaxy) for the ChangeDetection deploy-watermark path. Backend/Galaxy/GalaxyRepositoryOptions defaults to localhost ZB Integrated Security; runtime override comes from DriverConfig.Database section per plan.md §"Galaxy DriverConfig". Backend/Galaxy/GalaxyHierarchyRow + GalaxyAttributeRow are the row-shape DTOs (no required modifier — net48 lacks RequiredMemberAttribute and we'd need a polyfill shim like the existing IsExternalInit one; default-string init is simpler). System.Data.SqlClient 4.9.0 added (the same package the v1 Host uses; net48-compatible). Backend/DbBackedGalaxyBackend wraps the repository: DiscoverAsync builds a real DiscoverHierarchyResponse (groups attributes by gobject, resolves parent-by-tagname, maps category_id → human-readable template-category name mirroring v1 AlarmObjectFilter); ReadValuesAsync/WriteValuesAsync/HistoryReadAsync still surface "MXAccess code lift pending (Phase 2 Task B.1)" because runtime data values genuinely need the COM client; OpenSession/CloseSession/Subscribe/Unsubscribe/AlarmSubscribe/AlarmAck/Recycle return success without backend work (subscription ID is a synthetic counter for now). Live smoke tests (GalaxyRepositoryLiveSmokeTests) skip when localhost ZB is unreachable; when present they verify (1) TestConnection returns true, (2) GetHierarchy returns at least one deployed gobject with a non-empty TagName, (3) GetAttributes returns rows with FullTagReference matching the "tag.attribute" shape, (4) GetLastDeployTime returns a value, (5) DbBackedBackend.DiscoverAsync returns at least one gobject with attributes and a populated TemplateCategory. All 5 pass against the local Galaxy. Full solution 957 pass / 1 pre-existing Phase 0 baseline; the 494 v1 IntegrationTests + 6 v1 IntegrationTests-net48 tests still pass — legacy OtOpcUa.Host untouched. Remaining for the Phase 2 exit gate is the MXAccess COM client port itself (the v1 MxAccessClient partials + IMxProxy abstraction + StaPump-based Connect/Subscribe/Read/Write semantics) — Discover is now solved in DB-backed form, so the lift can focus exclusively on the runtime data-plane.

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

src/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host/Backend/Galaxy/GalaxyRepositoryOptions.cs

@@ -0,0 +1,13 @@
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Host.Backend.Galaxy;
+
+/// <summary>
+///     Connection settings for the Galaxy <c>ZB</c> repository database. Set from the
+///     <c>DriverConfig</c> JSON section <c>Database</c> per <c>plan.md</c> §"Galaxy DriverConfig".
+/// </summary>
+public sealed class GalaxyRepositoryOptions
+{
+    public string ConnectionString { get; init; } =
+        "Server=localhost;Database=ZB;Integrated Security=True;TrustServerCertificate=True;Encrypt=False;";
+
+    public int CommandTimeoutSeconds { get; init; } = 60;
+}