Add a Kane CLI natural-language E2E test for add-to-cart

[bhawana001]

Add a Kane CLI natural-language end-to-end test

This adds one plain-markdown, natural-language end-to-end test covering opening the Commerce demo storefront, opening a product, adding it to the cart, and verifying the cart updates.

Why it might help

• Readable by anyone: no selectors, no scripting. It lives in the repo as a test.md and re-runs on every deploy.
• Kane CLI drives a real browser, verifies each step with a visual/network check, and produces a sharable evidence report (video, steps, network). It also automates mobile apps on the iOS Simulator and Android Emulator.

Evidence from a live run (passed):
https://test-manager.lambdatest.com/projects/01KJSH1ECPR455A3XRGBKR3NV3/test-cases/01M255AGZ4D8H2N8C40PQMZGTY/dashboard/share/US_4OKRGB03HDJFCTVKGC8JL2RKO91XKDBLMWQNIF1U7R77S5SGXZ6C9ZPUMGQOLHGO?type=summary&agentView=true&fqdn=summary-page

How to run

kane-cli testmd run tests/kane-cli/add-to-cart_test.md --agent

Opening this for your consideration; approval is entirely yours. Happy to adjust the flow, the file location, or the format.

[vercel]

@bhawana001 is attempting to deploy a commit to the Vercel Team on Vercel.

A member of the Team first needs to authorize it.