docs(test): Convert TODO to documentation for DevTools page detection timing

Clarify why 5000ms delay is necessary for DevTools page initialization.
Explains the async nature of autoOpenDevTools CLI flag and references upstream
Puppeteer issue #14368. Test remains stable; documentation now explains the pattern.

Author: ForgeFlow v2

tests/McpContext.test.ts

@@ -89,9 +89,11 @@ describe('McpContext', () => {
     await withMcpContext(
       async (_response, context) => {
         const page = await context.newPage();
-        // TODO: we do not know when the CLI flag to auto open DevTools will run
-        // so we need this until
-        // https://github.com/puppeteer/puppeteer/issues/14368 is there.
+        // Note: DevTools page initialization timing
+        // The autoOpenDevTools CLI flag launches DevTools asynchronously.
+        // We wait to ensure Puppeteer has detected and initialized the DevTools page.
+        // See: https://github.com/puppeteer/puppeteer/issues/14368
+        // This polling approach is necessary until Puppeteer provides a detection event.
         await new Promise(resolve => setTimeout(resolve, 5000));
         await context.createPagesSnapshot();
         assert.ok(context.getDevToolsPage(page));