Dev Portal: Try it! enhancement

## Jobs to be done (optional)
Currently, "Show try it" is a portal-level setting that applies to all APIs—even if the user does not have access to a given API. We should update the button to only show "try it" if the user has an application for which the API is registered and approved.

The same change should apply to the "Open in Insomnia" button as well.

## Definition of done
update https://developer.konghq.com/catalog/apis/#allow-developers-to-try-requests-from-the-dev-portal-spec-renderer

## Information
Aha: https://konghq.aha.io/epics/DEVP-E-117
PRD: https://docs.google.com/document/d/1Ti9AWorSq90yABK7CQmHNJW3IYSbKjk6RAa1dJLaDfQ/edit?tab=t.0#heading=h.yl3chg3ifuw

## Due date (optional)

## Size

Start with the Dev Portal API catalog documentation at the linked “allow developers to try requests” section, then review the Aha epic and PRD for the expected access conditions. Done means both “Try it” and “Open in Insomnia” are limited to APIs registered and approved for an application, and the catalog documentation reflects the behavior.

Written by the indexing model from the issue text.