fix(ci): build project directly with RID instead of solution-level

Building a solution with -r is not supported (NETSDK1134). Build the
individual project with -r win-x64 instead.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: CrypticGuy

.github/workflows/ci.yml

@@ -23,10 +23,10 @@ jobs:
           dotnet-version: ${{ env.DOTNET_VERSION }}
 
       - name: Restore dependencies
-        run: dotnet restore ${{ github.workspace }}/CrossHairPlus.sln
+        run: dotnet restore ${{ github.workspace }}/CrossHairPlus/CrossHairPlus.csproj -r win-x64
 
       - name: Build
-        run: dotnet build ${{ github.workspace }}/CrossHairPlus.sln -c Release --no-restore
+        run: dotnet build ${{ github.workspace }}/CrossHairPlus/CrossHairPlus.csproj -c Release -r win-x64 --no-restore
 
       - name: Upload artifacts
         uses: actions/upload-artifact@v4