Implement LmxOpcUa server — all 6 phases complete

Full OPC UA server on .NET Framework 4.8 (x86) exposing AVEVA System
Platform Galaxy tags via MXAccess. Mirrors Galaxy object hierarchy as
OPC UA address space, translating contained-name browse paths to
tag-name runtime references.

Components implemented:
- Configuration: AppConfiguration with 4 sections, validator
- Domain: ConnectionState, Quality, Vtq, MxDataTypeMapper, error codes
- MxAccess: StaComThread, MxAccessClient (partial classes), MxProxyAdapter
  using strongly-typed ArchestrA.MxAccess COM interop
- Galaxy Repository: SQL queries (hierarchy, attributes, change detection),
  ChangeDetectionService with auto-rebuild on deploy
- OPC UA Server: LmxNodeManager (CustomNodeManager2), LmxOpcUaServer,
  OpcUaServerHost with programmatic config, SecurityPolicy None
- Status Dashboard: HTTP server with HTML/JSON/health endpoints
- Integration: Full 14-step startup, graceful shutdown, component wiring

175 tests (174 unit + 1 integration), all passing.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

gr/ddl/tables/attribute_reference.sql

@@ -0,0 +1,26 @@
+-- Table: attribute_reference
+CREATE TABLE [attribute_reference] (
+    [gobject_id] int NOT NULL,
+    [package_id] int NOT NULL,
+    [referring_mx_primitive_id] smallint NOT NULL DEFAULT ((0)),
+    [referring_mx_attribute_id] smallint NOT NULL DEFAULT ((0)),
+    [element_index] smallint NOT NULL DEFAULT ((0)),
+    [resolved_gobject_id] int NOT NULL DEFAULT ((0)),
+    [reference_string] nvarchar(700) NOT NULL DEFAULT (''),
+    [context_string] nvarchar(329) NOT NULL DEFAULT (''),
+    [object_signature] int NOT NULL DEFAULT ((0)),
+    [resolved_mx_primitive_id] smallint NOT NULL DEFAULT ((0)),
+    [resolved_mx_attribute_id] smallint NOT NULL DEFAULT ((0)),
+    [resolved_mx_property_id] smallint NOT NULL DEFAULT ((0)),
+    [attribute_signature] int NOT NULL DEFAULT ((0)),
+    [lock_type] int NOT NULL DEFAULT ((0)),
+    [is_valid] bit NOT NULL DEFAULT ((0)),
+    [attr_res_status] int NOT NULL DEFAULT ((0)),
+    [attribute_index] smallint NULL DEFAULT ((-1)),
+    CONSTRAINT [PK_attribute_reference] PRIMARY KEY ([gobject_id], [package_id], [referring_mx_primitive_id], [referring_mx_attribute_id], [element_index], [gobject_id], [package_id], [referring_mx_primitive_id], [gobject_id], [package_id], [referring_mx_primitive_id], [gobject_id], [package_id], [referring_mx_primitive_id])
+);
+GO
+
+ALTER TABLE [attribute_reference] ADD FOREIGN KEY ([referring_mx_primitive_id]) REFERENCES [primitive_instance] ([package_id]);
+GO
+