Implement comprehensive security scanning in CI/CD pipeline

[jobbykings]

Description

The CI pipeline has basic Trivy vulnerability scanning but lacks: dependency auditing (npm audit, cargo audit), secret scanning, SAST (static analysis), and container scanning. Add these security checks to catch vulnerabilities before they reach production.

Files to Modify

• .github/workflows/ci.yml — Add security scan jobs
• New: .github/workflows/security.yml — Dedicated security workflow
• New: .github/dependabot.yml — Automated dependency updates
• backend/package.json — Add audit scripts
• frontend/package.json — Add audit scripts

Definition of Done

• npm audit runs on every PR (backend + frontend), fails on critical/high
• cargo audit runs on contract changes
• GitHub CodeQL analysis enabled for JavaScript, TypeScript, Rust
• Dependabot configured for weekly dependency updates
• Secret scanning prevents committed credentials
• Security scan results visible in PR checks
• .github/SECURITY.md with vulnerability reporting process

[Andreschuks101]

Hello Maintainer. I am a fullstack dev and i've checked through this issue. I would love to resolve this issue as soon. Please assign

[grantfox-oss]

🦊 GrantFox — @Andreschuks101 has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #79)
2. Your PR will be reviewed by the Epondia maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign campaign!

@Andreschuks101's PR #94 was approved and merged by @jobbykings.

🏆 @Andreschuks101: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (188 total points). Track your full progress on GrantFox.

👏 Great work, @Andreschuks101! Keep contributing to Epondia.