Build GitHub Action: NEAR Contract Security Scan

Overview

Create a GitHub Action that scans NEAR smart contracts for common vulnerabilities and security issues as part of CI/CD.

Why This Matters

Smart contract security is critical. Automated scanning catches common issues before deployment, protecting users and building trust.

Technical Requirements

Action Usage

- name: Security Scan
  uses: near-actions/security-scan@v1
  with:
    contract-path: ./contracts
    severity-threshold: medium  # fail on medium+ issues
    output-format: sarif  # or json, markdown

Vulnerability Checks

1. Reentrancy patterns - Though NEAR prevents classic reentrancy
2. Integer overflow - Unchecked arithmetic
3. Access control - Missing permission checks
4. Panic conditions - Unbounded operations
5. Storage costs - Potential storage attacks
6. Cross-contract call safety - Callback handling
7. Upgrade safety - Migration vulnerabilities

Output

## Security Scan Results

### High Severity (1)
- **Unchecked arithmetic** in token.rs:45
  Multiplication may overflow. Use checked_mul.

### Medium Severity (2)
- **Missing access control** in admin.rs:23
  set_owner can be called by anyone.

### Low Severity (3)
...

Deliverables

1. GitHub Action with security rules
2. 10+ vulnerability patterns checked
3. SARIF output for GitHub Security tab
4. Customizable severity thresholds