Fix music-social issue body formatting by normalizing commit message to first line

[Copilot]

The music-social workflow was injecting full multi-line commit messages into generated “New Music Update” issues, which polluted the issue body (trailers like Agent-Logs-Url / Co-authored-by) and degraded readability. This update constrains the rendered commit message to a single clean subject line.

• Problem scope

  • Auto-generated issue content included commit trailers because github.event.head_commit.message was used as-is.

• Workflow change

  • In .github/workflows/music-social.yml, commit message extraction now:
    • uses a shared fallback constant (Mise à jour manuelle)
    • selects the first non-empty line only
    • preserves fallback behavior when message is empty/unset

• Resulting issue output

  • **Message** now consistently contains only the commit subject, preventing markdown noise in the issue template.

const defaultCommitMsg = 'Mise à jour manuelle';
const commitMsg = (process.env.COMMIT_MSG || defaultCommitMsg)
  .split('\n')
  .find(line => line.trim().length > 0) || defaultCommitMsg;

[bolt-new-by-stackblitz]

Run & review this pull request in StackBlitz Codeflow.

[Copilot]

Copilot wasn't able to review any files in this pull request.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.