[benbrandt]

Save agent configuration defaults only after a successful request, using the value in the authoritative response rather than the requested value.

Cycling, boolean switches and picker confirmation previously wrote the requested default before sending the RPC. Rejection or a normalized response could therefore leave incorrect preferences for future sessions. All three controls now share one response-handling path:

• No preference write while the request is pending or after rejection.
• Save the response's current select/boolean value, not the requested value.
• Do not overwrite preferences if the response removes the option, changes it to an unsupported kind, or does not offer the returned select value.

Release Notes:

• acp: Fixed agent configuration defaults being saved before acceptance or ignoring the agent's returned value.