refactor(commands): dedupe auth choice agent model notes

src/commands/auth-choice.apply-helpers.ts

@@ -0,0 +1,15 @@
+import type { ApplyAuthChoiceParams } from "./auth-choice.apply.js";
+
+export function createAuthChoiceAgentModelNoter(
+  params: ApplyAuthChoiceParams,
+): (model: string) => Promise<void> {
+  return async (model: string) => {
+    if (!params.agentId) {
+      return;
+    }
+    await params.prompter.note(
+      `Default model set to ${model} for agent "${params.agentId}".`,
+      "Model configured",
+    );
+  };
+}