> Application-level tenant scoping, AES-256-GCM encryption, and SSRF defenses

# Security & Permissions

## 5-Layer Security Architecture

1. **Transport Layer:** Strict TLS and `redirect: "manual"` proxy policies with fixed upstreams.
2. **Authentication:** Server-side token resolution and scoped API key verification (`internal/http/auth.go`).
3. **Authorization & RBAC:** Role hierarchy (Owner > Admin > Operator > Viewer).
4. **Tenant Isolation:** Application-level tenant scoping (`WHERE tenant_id = $N`, `store.WithTenantID(ctx)`, and `store.IsMasterScope(ctx)`).
5. **Execution Sandboxing:** Docker container isolation with restricted network capabilities and shell deny patterns.