Improve Flow Blueprint selection layout for limited widths on Create Instance form

### Description

On the final step of the Create Instance multi-step form, the Flow Blueprint selection doesn't render well when there is limited horizontal space available. Adjust the responsive layout so that:

- The categories section shifts upward (stacks above the blueprints) instead of staying side-by-side
- The blueprints regroup into 2 per row at constrained widths

Add appropriate breakpoints to ensure the layout adapts cleanly across screen sizes.

### Epic/Story

_No response_

### Have you provided an initial effort estimate for this issue?

I have provided an initial effort estimate