Fix Windows stage: per-project restore (no root solution)

.github/workflows/pr.yaml

@@ -710,11 +710,41 @@ jobs:
             9.0.x
             10.0.x
 
-      - name: Restore dependencies
-        run: dotnet restore
+      - name: Restore and build all projects
+        shell: pwsh
+        run: |
+          # Find solution file first (full recursive search), fall back to per-project restore
+          $solution = Get-ChildItem -Path . -Recurse -Include "*.sln", "*.slnx" -ErrorAction SilentlyContinue | Select-Object -First 1
+
+          if ($solution) {
+            Write-Host "Found solution: $($solution.FullName)"
+            dotnet restore $solution.FullName
+            if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
+            dotnet build $solution.FullName --no-restore --configuration Release
+            if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
+          } else {
+            Write-Host "No solution file found, restoring and building projects individually..."
+            $projects = @(Get-ChildItem -Path 'src' -Recurse -Filter '*.csproj' -ErrorAction SilentlyContinue)
+            if ($projects.Count -eq 0) {
+              $projects = @(Get-ChildItem -Path . -Recurse -Filter '*.csproj' -ErrorAction SilentlyContinue)
+            }
+
+            if ($projects.Count -eq 0) {
+              Write-Error "❌ No solution or project files found - nothing to build"
+              exit 1
+            }
+
+            foreach ($proj in $projects) {
+              Write-Host "Restoring $($proj.Name)"
+              dotnet restore $proj.FullName
+              if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
+              Write-Host "Building $($proj.Name)"
+              dotnet build $proj.FullName --no-restore --configuration Release
+              if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
+            }
+          }
 
-      - name: Build solution
-        run: dotnet build --no-restore --configuration Release
+          Write-Host "✅ All projects built successfully"
 
       - name: Run all .NET tests (.NET 5.0-10.0 and Framework 4.6.2-4.8.1)
         shell: pwsh