The initial repository had no application code and therefore no explicit controls for secrets, validation, authentication, authorization, logging, dependency review, or deployment hardening.

• Environment validation rejects short JWT secrets.
• Security headers reduce browser exploitation risk.
• CORS uses an allow-list.
• Request body size limits reduce resource exhaustion risk.
• Rate limiting provides brute-force and abuse protection foundation.
• Zod validation protects request boundaries.
• Sanitization is applied to user-controlled display text.
• JWT access and refresh token services support token rotation strategy through refresh token family IDs.
• RBAC primitives support middleware-based permission checks.
• Standard error contracts avoid leaking stack traces.
• Structured logs include request context.

Bearer-token API clients are not subject to cookie CSRF. Browser session flows should use Secure, HttpOnly, SameSite cookies and double-submit CSRF tokens for unsafe methods.

• Persist refresh tokens and detect token family reuse.
• Add Redis-backed rate limiting for multi-instance deployments.
• Add dependency vulnerability scanning once Deno is available in CI.
• Add mTLS or private networking for internal services.