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/galaxy.sql

@@ -0,0 +1,18 @@
+-- Table: galaxy
+CREATE TABLE [galaxy] (
+    [time_of_last_deploy] datetime NULL DEFAULT (getdate()),
+    [time_of_last_config_change] datetime NULL DEFAULT (getdate()),
+    [is_galaxy_installed] bit NOT NULL DEFAULT ((1)),
+    [time_of_last_reference_binding] datetime NULL DEFAULT (getdate()),
+    [timestamp_of_last_cascade] bigint NOT NULL DEFAULT ((1)),
+    [timestamp_of_last_visual_element_reference_bind] bigint NOT NULL DEFAULT ((0)),
+    [max_proxy_timestamp] bigint NOT NULL DEFAULT (CONVERT([bigint],@@dbts)),
+    [max_visual_element_timestamp] bigint NOT NULL DEFAULT (CONVERT([bigint],@@dbts)),
+    [is_migration_in_progress] bit NOT NULL DEFAULT ((0)),
+    [time_of_last_association_change] datetime NULL DEFAULT (getdate()),
+    [subscription_id] uniqueidentifier NULL,
+    [batch_id] uniqueidentifier NULL,
+    [iteration_id] int NOT NULL DEFAULT ((0))
+);
+GO
+