build: add self-contained portable publish variant (v0.2.1)

PublishSerialMcp target now inherits the GUI's SelfContained setting, so a --self-contained true publish also produces a runtime-free ETTerms.SerialMcp. Document both publish variants in ARCHITECTURE.md / CLAUDE.md: framework-dependent ETTerms_v{Version}\ and portable ETTerms_v{Version}_portable\ (no .NET runtime install needed).

src/ETTerms/ETTerms.csproj

@@ -37,14 +37,17 @@
     這樣單一 `dotnet publish src\ETTerms` 就會產生完整自洽的 bundle，
     且 McpRegistrar.ResolveServerExe() 解析的 <ETTerms.exe>\ETTerms.SerialMcp\ETTerms.SerialMcp.exe 必定存在。
     刻意放子資料夾：與 GUI 的相依 dll 隔離，避免互相覆蓋。
+    MCP 跟隨 GUI 的 self-contained 設定：框架相依版 → MCP 也框架相依；portable(self-contained)版 → MCP 也免 runtime。
   -->
   <Target Name="PublishSerialMcp" AfterTargets="Publish">
     <PropertyGroup>
       <_McpRid Condition="'$(RuntimeIdentifier)' != ''">$(RuntimeIdentifier)</_McpRid>
       <_McpRid Condition="'$(RuntimeIdentifier)' == ''">win-x64</_McpRid>
+      <_McpSelfContained Condition="'$(SelfContained)' != ''">$(SelfContained)</_McpSelfContained>
+      <_McpSelfContained Condition="'$(SelfContained)' == ''">false</_McpSelfContained>
     </PropertyGroup>
-    <Message Importance="high" Text="[ETTerms] Publishing ETTerms.SerialMcp -> $(PublishDir)ETTerms.SerialMcp" />
-    <Exec Command="dotnet publish &quot;$(MSBuildThisFileDirectory)..\ETTerms.SerialMcp\ETTerms.SerialMcp.csproj&quot; -c $(Configuration) -r $(_McpRid) --self-contained false -o &quot;$(PublishDir)ETTerms.SerialMcp&quot;" />
+    <Message Importance="high" Text="[ETTerms] Publishing ETTerms.SerialMcp -> $(PublishDir)ETTerms.SerialMcp (self-contained=$(_McpSelfContained))" />
+    <Exec Command="dotnet publish &quot;$(MSBuildThisFileDirectory)..\ETTerms.SerialMcp\ETTerms.SerialMcp.csproj&quot; -c $(Configuration) -r $(_McpRid) --self-contained $(_McpSelfContained) -o &quot;$(PublishDir)ETTerms.SerialMcp&quot;" />
   </Target>
 
 </Project>