The explicit MJ: AI Models id, or null/empty for none.
OptionalpreferredVoice: string | nullThe provider-native voice id (e.g. echo), or null/empty for none.
The JSON string, or null when nothing was overridden (keeps the mint identical to default).
Builds the
configOverridesJsonpayload for theStartRealtimeClientSessionmint from what the (authorization-gated) pickers chose — an explicit realtime model preference and/or a per-provider voice. The envelope ({"realtime":{"modelPreference":"<id>","voice":{"providers": {"openai":{"voice":"<v>"}}}}}) is the pinned server contract, merged into the effective config server-side (highest precedence).