[Card Grant] Add max expiration date

Card grants must expire within a certain time frame. For example, I don't want to allow a card grant to expire 100 years from now.

Let's set this max value to 3 years from now.

Start by locating the Card Grant creation or update entry point and any existing expiration validation, then inspect how dates are represented. Enforce the three-year maximum and verify boundary cases with the relevant test suite.

Written by the indexing model from the issue text.