fix(extension): stateless SW, pull tab state instead of ports (#596)

* feat(extension)!: make sw stateless; tabs update with pulling instead of pushing

* fix(extension): harden tab loading wait

* fix: safer `waitUntil`

* chore: comments

* chore: reduce polling logs

packages/extension/src/agent/TabsController.background.ts

@@ -1,5 +1,9 @@
 /**
  * background logics for TabsController
+ *
+ * Keep this stateless: pure request/response handlers only, no in-memory
+ * state, no ports, no event pushing. MV3 SW should be killed and restarted at
+ * any time (idle timeout, extension update) without special handling.
  */
 import type { TabAction } from './TabsController'
 
@@ -144,7 +148,6 @@ export function handleTabControlMessage(
 		}
 
 		case 'get_window_tabs': {
-			debug('get_window_tabs', payload)
 			chrome.tabs
 				.query({ windowId: payload.windowId })
 				.then((tabs) => {
@@ -161,41 +164,3 @@ export function handleTabControlMessage(
 			return
 	}
 }
-
-const tabEventPorts = new Set<chrome.runtime.Port>()
-
-function broadcastTabEvent(message: object) {
-	for (const port of tabEventPorts) {
-		port.postMessage(message)
-	}
-}
-
-/**
- * Port-based tab events: agents connect via `chrome.runtime.connect({ name: 'tab-events' })`
- * and receive tab change events through the port. Works for both extension pages and content scripts.
- */
-export function setupTabEventsPort() {
-	chrome.runtime.onConnect.addListener((port) => {
-		if (port.name !== 'tab-events') return
-
-		debug('port connected', port.sender?.tab?.id ?? port.sender?.url)
-		tabEventPorts.add(port)
-
-		port.onDisconnect.addListener(() => {
-			debug('port disconnected')
-			tabEventPorts.delete(port)
-		})
-	})
-
-	chrome.tabs.onCreated.addListener((tab) => {
-		broadcastTabEvent({ action: 'created', payload: { tab } })
-	})
-
-	chrome.tabs.onRemoved.addListener((tabId, removeInfo) => {
-		broadcastTabEvent({ action: 'removed', payload: { tabId, removeInfo } })
-	})
-
-	chrome.tabs.onUpdated.addListener((tabId, changeInfo, tab) => {
-		broadcastTabEvent({ action: 'updated', payload: { tabId, changeInfo, tab } })
-	})
-}