Handle Districts

Create Card Components that are rendered for District templates, possibly with bespoke node types and allow navigating to them.

In a later round we may add displaying the districts on the map but I think this is out of scope for MVP

Start by locating the district templates, existing Card Components, and the navigation entry points used to render and open other template content. Done means district templates render their cards, bespoke node types are supported if needed, and users can navigate to those districts; map display remains out of scope for the MVP.

Written by the indexing model from the issue text.