Enhance Node.js CI workflow with security report uploads and cleanup

[AsjadJDawre]

Summary

This PR improves the existing Node.js CI workflow for better maintainability and visibility of security scans.

Changes Made

• ✅ Added workflow_dispatch trigger for manual runs.
• ✅ Uploaded Trivy and Gitleaks reports as build artifacts for easy review in the GitHub Actions UI.
• ✅ Fixed Trivy output format to JSON for compatibility.
• ✅ Cleaned and structured job sequence (install → security-check → test → build).
• ✅ Improved lint step handling and logging.

Benefits

• Clearer job structure and execution order.
• Security scan results can now be reviewed directly from the Actions tab.
• CI is more developer-friendly and production-aligned.

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Tested on fork: ✅ Yes
Node versions: 18.x, 20.x, 22.x