sync dataModel from client to agent

[wrenj]

collaborative editing usecases require the agent to know updates to the datamodel from the client

eg "show time off form" -> user edits form -> "okay submit the off form" (agent needs to know updated values)

or

"show time off form" -> user sets date to last year -> agent needs an update to validate the date and send a UI update

We'll likely need different modes for dataModel sync

• REALTIME (on every update tell the agent)
• ON_ACTION (send all updates the next time we send an A2A message to it via userAction)
• ON_MESSAGE (send all updates the next time we send an A2A message to it) -> complexity here is orchestrator may not route to that agent

Prefer making a new event type from client not called updateDataModel (we got feedback in a2a ui events that have the same event name from client->server and server->client really confused people). Maybe clientSyncDataModel or something idk