Show Active + Upcoming Rebates in Public API

Problem Statement:
Clients can’t see rebates that are scheduled to start in the future. Our current validation logic only exposes rebates with status “active,” even though upcoming rebates are already stored in the database. This creates confusion and limits client planning.

Goals:

• Surface upcoming rebates to clients before they go live.

• Provide clear, machine-readable fields so clients can decide how to display or filter rebate timelines.

• Reduce support questions about “missing” rebates.