Functional overview

At this step, only top-level cards are shown. For example "User stories".
Cards always appear on the left "column" without regard for their actual "column" (and the mapping to their specific list field). There is no distinction of "solo items" (artifacts that do not have children), they are also shown on the left-hand side.

Technical overview

No realtime at this step.

The REST route will live in the new taskboard plugin and will be named something like "taskboard/:id/cards".
The REST route will return id, title, cross-reference (like story #a123) and tracker color. It must return the cards in the correct ranking order (by "Artifact priority", also named "Rank").*

The Title semantic can also be assigned to a Text field (HTML). In this case, we will strip all tags on the card with DOM Purify

In case of REST error, the app will show a "global error state". At this stage, since almost nothing is shown, we will show an "app error state" (like we have an empty state).