Add GitHub Actions job summary step to SonarCloud workflow

Agent-Logs-Url: https://github.com/304NotModified/SLNX-validator/sessions/5a7193d6-1ad7-45a2-98a1-edf1176dc573

Co-authored-by: 304NotModified <5808377+304NotModified@users.noreply.github.com>

Author: Copilot

.github/workflows/sonarcloud.yml

@@ -53,3 +53,10 @@ jobs:
         env:
           SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
         run: dotnet sonarscanner end /d:sonar.token="${SONAR_TOKEN}"
+
+      - name: SonarCloud summary
+        if: always()
+        run: |
+          echo "## 🔍 SonarCloud Analysis" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          echo "View full results: [sonarcloud.io/project/overview?id=slnx-validator](https://sonarcloud.io/project/overview?id=slnx-validator)" >> $GITHUB_STEP_SUMMARY