Use the following as the Desired outcome for the brief above.
Read https://openiap.dev/commerce-example/integration-brief.md and follow its linked guides and example code for my role.

Build a local backend for monthly Premium subscriptions.
Use this project's stack and fictional purchases for the first demo.
Alice gets Premium after her verified purchase is connected to her.
Canceling renewal keeps access until expiry. Bob cannot claim Alice's purchase.

Implement this in my project. Use fictional data first.
For verification, read http://127.0.0.1:4187/commerce-example/experience-verification.md.
Download its linked example source into a separate temporary folder, then run npm ci and npm test there (Bun is required).
Use the example's checks as a reference, then run equivalent checks against MY implementation for this role.
Fix failures and rerun. Show the changed files, commands, actual results, and anything not tested.
Show my running app or service. Passing the example alone does not verify my project.
