feat!: require user to provide LLM api. do not fallback to demo LLM

BREAKING CHANGE: LLM API will be required for agent constructor

packages/page-agent/src/PageAgent.ts

@@ -95,7 +95,7 @@ export class PageAgent extends EventTarget {
 	/** History records */
 	history: AgentHistory[] = []
 
-	constructor(config: PageAgentConfig = {}) {
+	constructor(config: PageAgentConfig) {
 		super()
 
 		this.config = config

packages/page-agent/src/umd.ts

@@ -35,7 +35,12 @@ setTimeout(() => {
 		window.pageAgent = new PageAgent(config)
 	} else {
 		console.log('🚀 page-agent.js no current script detected, using default demo config')
-		window.pageAgent = new PageAgent()
+		const config: PageAgentConfig = {
+			model: DEMO_MODEL,
+			baseURL: DEMO_BASE_URL,
+			apiKey: DEMO_API_KEY,
+		}
+		window.pageAgent = new PageAgent(config)
 	}
 
 	console.log('🚀 page-agent.js initialized with config:', window.pageAgent.config)