test(ci): split netem interop summaries into local and GitHub-specific reports

Create separate markdown files for local browsing with relative links and GitHub Action summaries with artifact notices. This ensures the GitHub Step Summary remains readable and informative without broken links.

.github/workflows/interop-netem.yml

@@ -60,11 +60,11 @@ jobs:
       - name: Append netem interop summary
         if: always()
         run: |
-          latest_summary="$(find target/interop-netem -mindepth 2 -maxdepth 2 -name summary.md -type f -print 2>/dev/null | sort | tail -n 1)"
+          latest_summary="$(find target/interop-netem -mindepth 2 -maxdepth 2 -name github-step-summary.md -type f -print 2>/dev/null | sort | tail -n 1)"
           if [ -n "$latest_summary" ]; then
             cat "$latest_summary" >> "$GITHUB_STEP_SUMMARY"
           else
-            echo "No netem interop summary.md found." >> "$GITHUB_STEP_SUMMARY"
+            echo "No netem interop github-step-summary.md found." >> "$GITHUB_STEP_SUMMARY"
           fi
 
       - name: Upload netem interop artifacts