feat(ci): add cross-contract integration tests + CI test workflow

[Jenix777]

Description

Related Issues

Closes #

Type of Change

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• ⚡ Performance improvement
• ♻️ Refactor / Code cleanliness
• 📝 Documentation update
• 🔧 Tooling / CI configuration

Checklist

• My code follows the code style guidelines of this project.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation (if applicable).
• My changes generate no new compiler warnings or lints.
• I have added tests that prove my fix is effective or that my feature works (if applicable).
• All new and existing tests pass locally.

Additional Notes / Screenshots