feat: Phase 9 Serial MCP server + app icon & version title (v0.2.0)

Phase 9 (AI integration) complete -- AI agents can send/receive serial
while the user watches live in the GUI, with the GUI as sole COM-port owner.

- ETTerms.SerialMcp: stdio MCP server (net8.0 + ModelContextProtocol SDK)
  exposing serial_list / serial_attach / serial_write / serial_read
  (waitFor + timeoutMs) / serial_detach; forwards over named pipe.
- GUI SerialBridgeServer (pipe etterms-serial) + SerialBridge endpoint;
  SessionPage.WriteFromAi echoes MCP-sourced TX tagged [AI] (magenta).
- App icon: window title bar / taskbar / exe now use Choco_256x256.ico
  (embedded via AppAssets); title bar shows ETTerms Version vX.Y.Z.
- About page: large Choco icon (Zoom, no crop).
- Docs: ARCHITECTURE.md + CLAUDE.md mark Phase 9 done; docs/serial-mcp-guide.md.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/ETTerms.SerialMcp/Program.cs

@@ -0,0 +1,17 @@
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+
+// stdio MCP server：把 ETTerms GUI 持有的 serial session 暴露給 AI（Kiro / Claude CLI）。
+// 自己不開 COM port，所有收發經 named pipe 轉給 GUI 的 SerialBridgeServer。
+var builder = Host.CreateApplicationBuilder(args);
+
+// stdio 傳輸：stdout 專供 JSON-RPC，log 一律走 stderr，否則會污染協議。
+builder.Logging.AddConsole(o => o.LogToStandardErrorThreshold = LogLevel.Trace);
+
+builder.Services
+    .AddMcpServer()
+    .WithStdioServerTransport()
+    .WithToolsFromAssembly();
+
+await builder.Build().RunAsync();