Introducing AI Transport v0.4.0

What this post added

Introduced database hydration to AI Transport, allowing applications to persist completed AI conversation runs to an external store (e.g., a database). This enables reconciliation of stored history with live activity, providing realtime visibility and supporting multi-device continuity, resumable streaming, and bidirectional control. The implementation involves persisting immutable completed runs and using `loadUntil` to fetch messages newer than the latest stored one for both agent and client hydration.