Release Realtime support in client and CLI

[erickkkyt]

Summary

• sync generated types and contract lock to BeatAPI/beatapi-examples Realtime baseline
• add Realtime session create, get, and close methods to beatapi-client
• add matching beatapi CLI commands with exact duration, origin, metadata, and idempotency handling
• prepare beatapi-client and beatapi version 0.2.0
• document the server/browser credential boundary

Verification

• npm run verify
• package install and executable smoke test
• npm audit: 0 vulnerabilities

Merge order

Merge BeatAPI/beatapi-examples#7 first.