Gate music-social issue creation to real music-content additions (#253)

* Initial plan

* fix: only open music-social issue for actual added music content

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

Author: Copilot

.github/workflows/music-social.yml

@@ -58,14 +58,15 @@ jobs:
           echo "$ADDED" > /tmp/music_changes.txt
 
           # Détecter la présence de nouveaux titres (balises audio ou liens)
-          if echo "$DIFF" | grep -qiE '(audio|track|mix|set|release|soundcloud|youtube)'; then
+          if echo "$ADDED" | grep -qiE '(audio|track|mix|set|release|soundcloud|youtube)'; then
             echo "has_music_content=true" >> "$GITHUB_OUTPUT"
           else
             echo "has_music_content=false" >> "$GITHUB_OUTPUT"
           fi
 
       # Créer une issue GitHub récapitulative de la mise à jour musicale
       - name: Créer une issue "New Music Update"
+        if: steps.diff.outputs.has_music_content == 'true'
         uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v7
         env:
           LINES_ADDED: ${{ steps.diff.outputs.lines_added }}