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/instance.sql

@@ -0,0 +1,13 @@
+-- Table: instance
+CREATE TABLE [instance] (
+    [gobject_id] int NOT NULL,
+    [mx_platform_id] smallint NOT NULL DEFAULT ((0)),
+    [mx_engine_id] smallint NOT NULL DEFAULT ((0)),
+    [mx_object_id] smallint NOT NULL DEFAULT ((0)),
+    CONSTRAINT [PK_instance] PRIMARY KEY ([gobject_id], [gobject_id])
+);
+GO
+
+ALTER TABLE [instance] ADD FOREIGN KEY ([gobject_id]) REFERENCES [gobject] ([gobject_id]);
+GO
+