fix stale popup warnings leaking across executions on error path

Oracle review found that popupWarnings was only drained on the success
path. If execute() threw, warnings would leak into the next unrelated
call. Now drain in both success and catch paths.

Also guard indexOf returning -1 when popup isn't in context.pages() yet.

playwriter/src/executor.ts

@@ -318,7 +318,8 @@ export class PlaywrightExecutor {
     page.on('popup', (popup) => {
       const context = page.context()
       const pages = context.pages()
-      const pageIndex = pages.indexOf(popup)
+      const rawIndex = pages.indexOf(popup)
+      const pageIndex = rawIndex >= 0 ? String(rawIndex) : 'unknown'
       const url = popup.url()
       this.popupWarnings.push(
         `Popup window detected (page index ${pageIndex}, url: ${url}). ` +
@@ -918,12 +919,16 @@ export class PlaywrightExecutor {
       this.logger.error('Error in execute:', errorStack)
 
       const logsText = formatConsoleLogs(consoleLogs, 'Console output (before error)')
+      const popupText = this.popupWarnings.length > 0
+        ? this.popupWarnings.map((w) => `[WARNING] ${w}`).join('\n') + '\n'
+        : ''
+      this.popupWarnings = []
       const resetHint = isTimeoutError
         ? ''
         : '\n\n[HINT: If this is an internal Playwright error, page/browser closed, or connection issue, call reset to reconnect.]'
 
       return {
-        text: `${logsText}\nError executing code: ${error.message}\n${errorStack}${resetHint}`,
+        text: `${logsText}${popupText}\nError executing code: ${error.message}\n${errorStack}${resetHint}`,
         images: [],
         isError: true,
       }