Address PR review: fix README pack metadata, doc hierarchy, and snupkg push

- Change None Include to None Update for README.md in both SDK csproj
  files to avoid NETSDK1022 duplicate item errors in SDK-style projects
- Demote '.NET SDK Packages' to h3 subsection under '.NET SDK Quickstart'
  so the Quickstart heading is not left empty
- Add snupkg push step to publish workflow so symbol packages reach
  NuGet.org alongside the main nupkg files

Author: TianqiZhang

.github/workflows/publish-sdk-packages.yml

@@ -42,3 +42,7 @@ jobs:
             --api-key "$NUGET_API_KEY" \
             --source "https://api.nuget.org/v3/index.json" \
             --skip-duplicate
+          dotnet nuget push artifacts/nuget/*.snupkg \
+            --api-key "$NUGET_API_KEY" \
+            --source "https://api.nuget.org/v3/index.json" \
+            --skip-duplicate

README.md

@@ -103,7 +103,7 @@ All APIs are scoped by route:
 
 ## .NET SDK Quickstart
 
-## .NET SDK Packages
+### .NET SDK Packages
 
 - `MemNet.Client`: https://www.nuget.org/packages/MemNet.Client
 - `MemNet.AgentMemory`: https://www.nuget.org/packages/MemNet.AgentMemory

src/MemNet.AgentMemory/MemNet.AgentMemory.csproj

@@ -21,7 +21,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <None Include="README.md" Pack="true" PackagePath="/" />
+    <None Update="README.md" Pack="true" PackagePath="/" />
   </ItemGroup>
 
   <ItemGroup>

src/MemNet.Client/MemNet.Client.csproj

@@ -17,7 +17,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <None Include="README.md" Pack="true" PackagePath="/" />
+    <None Update="README.md" Pack="true" PackagePath="/" />
   </ItemGroup>
 
   <ItemGroup>