Add web security guard

[ayalaphiscan]

What

Adds web-security-guard — a security plugin that makes Claude security-aware by default.

• 6 skills: site hardening (headers, CSP, OWASP Top 10), secure authentication (email verification, 2FA/TOTP, passkeys), payment privacy (Stripe/PayPal, webhook signatures, PCI/GDPR), attack defense (zero-dependency WAF middleware with lockdown mode), 4-layer Fortress architecture (invisible reverse proxy, hidden origin, WireGuard, offline vault — with ready-to-deploy templates), GitHub security workflows (CodeQL, Dependabot, secret scanning)
• 2 commands: /proteggi-sito (install all protections), /security-audit (full audit with report)
• MIT licensed · upstream repo: https://github.com/ayalaphiscan/web-security-guard

Changes

• plugins/web-security-guard/ — full plugin content
• Entry in .claude-plugin/marketplace.json
• Entry in README.md and README-zh.md under Security, Compliance, & Legal