feat(ext): handcraft the whole ext from scratch

AI coding doesn't work for MV3 extensions.
Threading was an unfixable mess.
Removed everything and rebuilt by hand.

packages/extension/src/agent/MultiPageAgent.ts

@@ -0,0 +1,40 @@
+import { PageAgentConfig, PageAgentCore } from '@page-agent/core'
+
+import { RemotePageController } from './RemotePageController'
+import { TabsController } from './TabsController'
+import { createTabTools } from './tabTools'
+
+export class MultiPageAgent extends PageAgentCore {
+	constructor(config: Omit<PageAgentConfig, 'pageController'>) {
+		const tabsController = new TabsController()
+		const pageController = new RemotePageController()
+		pageController.tabsController = tabsController
+		const customTools = createTabTools(tabsController)
+
+		super({
+			...config,
+			pageController: pageController as any,
+			customTools: customTools,
+
+			onBeforeTask: async (agent) => {
+				await tabsController.init(agent.taskId)
+
+				await chrome.storage.local.set({
+					isAgentRunning: true,
+				})
+			},
+
+			onAfterTask: async () => {
+				await chrome.storage.local.set({
+					isAgentRunning: false,
+				})
+			},
+
+			onDispose: () => {
+				chrome.storage.local.set({
+					isAgentRunning: false,
+				})
+			},
+		})
+	}
+}