Configure which observations trigger real-time alerts in your session. Default: severity >= warn only.

Examples:
- Watch only exceptions: kinds=['exception'], severity_min='error'
- Monitor a specific app: origins=['app:user-api']
- Listen for messages from another agent: origins=['app:agent-b'], severity_min='info'
- Reset to default: call with no parameters

Subscription persists for the session. Call again to change filters.