Summary

Complete the remaining Arc upstream reliability fixes for observable-query teardown, SSE reconnection, client readiness, and nested command forms.

Added

Exposed observable-query readiness through the TypeScript and React query-result APIs. (#2589)
Added runtime binding support for custom command-form fields rendered through opaque layouts. (#2582)

Prevented subscription teardown from being logged as an emission-guard security failure or sending late stream messages. (#2588)
Re-sent active SSE subscriptions when a connection ID changes while a subscribe request is in flight. (#2597)
Bound nested CommandForm fields while preserving custom layouts, columns, population metadata, and validation behavior. (#2582)