Block the merge when a PR ships a vulnerability: a CI security gate with Synapse

A new CI security gate utilizing Synapse, an open source security scanner written in Go, prevents vulnerabilities from entering the main branch. When a pull request introduces a security flaw, the CI process fails, and a comment provides specific fix instructions. Results are integrated into the GitHub Code scanning tab, ensuring the merge button remains locked until the issue is resolved. A public demo repository is available to showcase this functional security implementation.