sigiro hosted telemetry API

For a hosted human account, use the hosted onboarding guide: run sigiro signup --name "Your Name" --email you@example.com for first-time signup, or sigiro auth login for an existing account. Sigiro emails a six-digit OTP for signup, completes OAuth device authorization internally, and stores refresh/access credentials in the OS credential store; sigiro auth token prints a short-lived access token. For software that needs its own delegated identity, follow Onboard an agent with Agent Auth; the SDK registers dynamically and, after one user approval, signs capability-scoped bearer tokens for https://sigiro.com.