Show category and publisher descriptions on the game detail page

[github-actions]

The categories and publishers tables already include a description field, but the game detail page only shows their names. Surfacing these descriptions gives backers helpful context about who is behind a game and what kind of game it is, with no schema changes required.

Acceptance criteria

• The game detail page displays the category description when one is available
• The game detail page displays the publisher description when one is available
• Missing descriptions are handled gracefully (the section is hidden rather than showing empty content)
• The new content follows the project's styling and accessibility guidelines and includes data-testid attributes
• The data-access helper is updated to include the description fields, with unit tests covering the change, and Playwright e2e tests verify the descriptions render