Add secure Realtime Video MCP tools

[erickkkyt]

Summary

• sync the public OpenAPI, official client runtime, and canonical Skill baselines
• add Realtime session create, get, and close MCP tools
• store the one-time browser client secret in a mode-0600 local file and keep it out of model-visible results
• add exact-origin, idempotency, rollback, protocol, and secret-redaction tests
• prepare plugin version 0.2.0 and submission assets

Verification

• npm run verify
• 19 MCP tools exercised and classified
• npm audit: 0 vulnerabilities

Merge order

Merge BeatAPI/beatapi-examples#7, BeatAPI/beatapi-cli#3, and BeatAPI/beatapi-skill#1 first.