Overview

Marks a proposal as rejected. This changes the proposal's status to Rejected, logs the action, and optionally refunds any online payment that was made against the proposal.

What this endpoint does:

1. Loads the proposal by proposalID
2. Validates the proposal can be rejected (permission + status check)
3. Checks for refundable online payments and automatically refunds if applicable
4. Reverses any pre-bind agency invoices
5. Sets the proposal status to Rejected
6. Updates related policy change records to Rejected status
7. For renewals: handles book-of-business transfer implications
8. Logs the rejection via workflow log and fires a status change event