Version updates: Medusa.js 2.7.0 + NextJs 15.3.1

[AmeerRizvi]

Backend and frontend upgraded to Medusa.js 2.7.0 and Next.js 15.3.1.

• Fixed package.json for both backend and frontend
• Fixed awaits for NextJs 15
• Eventsource updated to 3.0.6
• Formstate actions fixed

Stable.

[vercel]

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

A member of the Team first needs to authorize it.