fix Runtime.enable race condition with event-based synchronization

Replace arbitrary sleep(200ms) with proper wait for Runtime.executionContextCreated
event in the relay server. This ensures pages are fully ready before Runtime.enable
returns to Playwright, fixing intermittent 'page not found' errors.

extension/src/background.ts

@@ -232,7 +232,7 @@ async function handleCommand(msg: ExtensionCommandMessage): Promise<any> {
       }
       try {
         await chrome.debugger.sendCommand(debuggee, 'Runtime.disable')
-        await sleep(400)
+        await sleep(200)
       } catch (e) {
         logger.debug('Error disabling Runtime (ignoring):', e)
       }
@@ -507,15 +507,7 @@ function handleConnectionClose(reason: string, code: number): void {
     return
   }
 
-  store.setState((state) => {
-    const newTabs = new Map(state.tabs)
-    for (const [tabId, tab] of newTabs) {
-      if (tab.state === 'connected') {
-        newTabs.set(tabId, { ...tab, state: 'connecting' })
-      }
-    }
-    return { tabs: newTabs, connectionState: 'disconnected', errorText: undefined }
-  })
+  store.setState({ connectionState: 'disconnected', errorText: undefined })
 
   if (tabs.size > 0) {
     logger.debug('Tabs still connected, triggering reconnection')