refactor: dedupe agent and browser cli helpers

src/agents/live-test-helpers.ts

@@ -0,0 +1,24 @@
+export const LIVE_OK_PROMPT = "Reply with the word ok.";
+
+export function createSingleUserPromptMessage(content = LIVE_OK_PROMPT) {
+  return [
+    {
+      role: "user" as const,
+      content,
+      timestamp: Date.now(),
+    },
+  ];
+}
+
+export function extractNonEmptyAssistantText(
+  content: Array<{
+    type?: string;
+    text?: string;
+  }>,
+) {
+  return content
+    .filter((block) => block.type === "text")
+    .map((block) => block.text?.trim() ?? "")
+    .filter(Boolean)
+    .join(" ");
+}