Enable IL trimming to reduce 207-assembly WASM payload

Without trimming the app ships 207 assemblies (~50 MB) causing GitHub Pages
CDN to 503-rate-limit some parallel requests. Trimming removes unused BCL
types and should cut file count significantly.

HealthKitData.Core, EPPlus, and Newtonsoft.Json are rooted (not trimmed)
because they use reflection internally.

https://claude.ai/code/session_01GwHuC47PH81Zw3EUfgkrYN

Author: claude

src/HealthNerd.Wasm/HealthNerd.Wasm.csproj

@@ -4,8 +4,9 @@
     <TargetFramework>net8.0</TargetFramework>
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
-    <!-- Trimming disabled: HealthKitData.Core and EPPlus use XML reflection -->
-    <PublishTrimmed>false</PublishTrimmed>
+    <!-- Trimming enabled to reduce the 200+ assembly payload.
+         Reflection-heavy packages are rooted via TrimmerRootAssembly below. -->
+    <PublishTrimmed>true</PublishTrimmed>
   </PropertyGroup>
 
   <ItemGroup>
@@ -18,4 +19,12 @@
     <PackageReference Include="Disposing" Version="1.0.0" />
   </ItemGroup>
 
+  <!-- Preserve assemblies that use reflection internally so the trimmer
+       doesn't remove members they need at runtime. -->
+  <ItemGroup>
+    <TrimmerRootAssembly Include="HealthKitData.Core" />
+    <TrimmerRootAssembly Include="EPPlus" />
+    <TrimmerRootAssembly Include="Newtonsoft.Json" />
+  </ItemGroup>
+
 </Project>