Add parallel task execution cookbook guide

[dprevoznik]

Summary

• add a Parallel Task Execution card to the common patterns cookbook section
• add a concise guide covering shared profiles, named Playwright executors, bounded concurrency, and cleanup
• add the guide to the Common patterns navigation group

Validation

• git diff --check
• python3 -m json.tool docs.json
• cookbook card image validation for images/cookbooks/*.png
• Mintlify preview not run because the mintlify CLI is not installed in this environment

---

Note

Low Risk
Documentation-only changes with no runtime, auth, or data-handling impact.

Overview
Adds documentation for running multiple tasks in parallel on one profiled browser using named Playwright executors (one tab per lane), with profile save_changes, concurrency limits, and executor/browser cleanup.

Introduces browsers/parallel-task-execution.mdx with a short “how it works” flow, TypeScript/Python examples (Promise.all / asyncio.gather), and a link to the full cookbooks repo example. The Cookbooks page gains a Parallel Task Execution card under common patterns pointing at the new guide.

^{Reviewed by Cursor Bugbot for commit 96937a1. Bugbot is set up for automated code reviews on this repo. Configure here.}

[mintlify]

Preview deployment for your docs. Learn more about Mintlify Previews.

Project	Status	Preview	Updated
Kernel	🟢 Ready	View Preview	Oct 10, 2026, 1:06 AM

💡 Tip: Enable Automations to automatically generate PRs for you.

[dprevoznik]

i also ran both snippets end-to-end:

TypeScript: two named executors navigated successfully and returned page titles.
Python: same flow succeeded with asyncio.gather.
Both cleaned up their executors and browser afterward.