Add Oryon scan workflow

[Guayamose]

Adds a GitHub Actions workflow that runs the Oryon scanner on push, pull request, and manual dispatch.

What changed:

• checks out the Foodly repository into repo/ so the scanner only scans application code;
• checks out the private Guayamose/oryon-action repository through a read-only deploy key;
• normalizes the repository remote so the runner matches the existing Oryon Project-Foodly binding;
• runs Oryon with upload and AI enabled;
• uploads JSON/SARIF/Markdown artifacts from repo/.oryon/.

Validation:

• workflow run 25563022777 completed successfully;
• Oryon uploaded scan 243 to project 3;
• GitHub artifact oryon-security-scan uploaded successfully.