fix(browser): host agent browser in workbench

src/shared/browser-host.ts

@@ -10,6 +10,10 @@ export interface BrowserHostView {
   visible: boolean
   error?: string
 }
+export interface BrowserHostEvent {
+  type: 'opened'
+  view: BrowserHostView
+}
 export interface BrowserHostApi {
   create(sessionId?: string, initialUrl?: string): Promise<BrowserHostView>
   get(id: string, sessionId?: string): Promise<BrowserHostView>
@@ -20,6 +24,7 @@ export interface BrowserHostApi {
   bounds(id: string, bounds: BrowserHostBounds | null, sessionId?: string): Promise<void>
   close(id: string, sessionId?: string): Promise<void>
   rebind(id: string, previousSessionId: string | undefined, nextSessionId: string): Promise<BrowserHostView>
+  onEvent(listener: (event: BrowserHostEvent) => void): () => void
 }
 
 export function normalizeBrowserHostUrl(value: string): string {