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_definition.sql

@@ -0,0 +1,24 @@
+-- Table: attribute_definition
+CREATE TABLE [attribute_definition] (
+    [attribute_definition_id] int NOT NULL,
+    [primitive_definition_id] int NOT NULL,
+    [attribute_name] nvarchar(329) NOT NULL,
+    [mx_attribute_id] smallint NOT NULL,
+    [has_config_set_handler] bit NOT NULL,
+    [mx_data_type] smallint NOT NULL,
+    [is_array] bit NOT NULL,
+    [security_classification] smallint NOT NULL,
+    [security_classification_needs_deployed] bit NOT NULL,
+    [mx_attribute_category] int NOT NULL,
+    [is_frequently_accessed] bit NOT NULL,
+    [is_locked] bit NOT NULL,
+    [is_locked_needs_deployed] bit NOT NULL,
+    [mx_value] text(2147483647) NOT NULL,
+    [mx_value_needs_deployed] bit NOT NULL,
+    CONSTRAINT [PK_attribute_definition] PRIMARY KEY ([primitive_definition_id], [mx_attribute_id], [primitive_definition_id])
+);
+GO
+
+ALTER TABLE [attribute_definition] ADD FOREIGN KEY ([primitive_definition_id]) REFERENCES [primitive_definition] ([primitive_definition_id]);
+GO
+