Complete security remediation workflow. Scans code for vulnerabilities using Snyk, fixes them, validates the fix, and optionally creates a PR. Supports both single-issue and batch mode for multiple vulnerabilities. Use this skill when: - User asks to fix security vulnerabilities - User mentions "snyk fix", "security fix", or "remediate vulnerabilities" - User wants to fix a specific CVE, Snyk ID, or vulnerability type (XSS, SQL injection, path traversal, etc.) - User wants to upgrade a vulnerable dependency - User asks to "fix all" vulnerabilities or "fix all high/critical" issues (batch mode)