fix(app): new session uses agent model/variant

packages/app/src/pages/session/session-model-helpers.ts

@@ -3,6 +3,12 @@ import { batch } from "solid-js"
 
 type Local = {
   agent: {
+    current():
+      | {
+          model?: UserMessage["model"]
+          variant?: string
+        }
+      | undefined
     set(name: string | undefined): void
   }
   model: {
@@ -19,6 +25,15 @@ type Local = {
   }
 }
 
+export const resetSessionModel = (local: Local) => {
+  const agent = local.agent.current()
+  if (!agent) return
+  batch(() => {
+    local.model.set(agent.model)
+    local.model.variant.set(agent.variant)
+  })
+}
+
 export const syncSessionModel = (local: Local, msg: UserMessage) => {
   batch(() => {
     local.agent.set(msg.agent)