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/operation_message.sql

@@ -0,0 +1,13 @@
+-- Table: operation_message
+CREATE TABLE [operation_message] (
+    [message_id] int NOT NULL,
+    [operation_id] int NOT NULL,
+    [message_text] nvarchar(300) NOT NULL,
+    [message_time] datetime NOT NULL DEFAULT (getdate()),
+    CONSTRAINT [PK_operation_message] PRIMARY KEY ([message_id], [operation_id])
+);
+GO
+
+ALTER TABLE [operation_message] ADD FOREIGN KEY ([operation_id]) REFERENCES [operation] ([operation_id]);
+GO
+