fix: use inline setInterval instead of EventLoopKeepalive import

EventLoopKeepalive is not exported from yield.ts on main.
Use setInterval + unref() directly, matching the pattern in
keepaliveWhile(). Biome import order also fixed (type imports
before value imports within the same group).

packages/agent/src/agent.ts

@@ -34,7 +34,6 @@ import type {
 	StreamFn,
 	ToolCallContext,
 } from "./types";
-import { EventLoopKeepalive } from "./utils/yield";
 
 /**
  * Default convertToLlm: Keep only LLM-compatible messages, convert attachments.
@@ -858,7 +857,8 @@ export class Agent {
 		if (!model) throw new Error("No model configured");
 
 		let skipInitialSteeringPoll = options?.skipInitialSteeringPoll === true;
-		const keepalive = new EventLoopKeepalive();
+		const keepalive = setInterval(() => {}, 86_400_000);
+		keepalive.unref();
 		const { promise, resolve } = Promise.withResolvers<void>();
 		this.#runningPrompt = promise;
 		this.#resolveRunningPrompt = resolve;
@@ -1063,7 +1063,7 @@ export class Agent {
 			this.#state.error = err?.message || String(err);
 			this.#emit({ type: "agent_end", messages: [errorMsg] });
 		} finally {
-			keepalive.dispose();
+			clearInterval(keepalive);
 			this.#state.isStreaming = false;
 			this.#state.streamMessage = null;
 			this.#state.pendingToolCalls = new Set<string>();