"Clicking on everything produces no visible effect" — the cause was upstream of the controls, and it
is the same defect as the invisible alert box (TASK 47):
- `Source.DisplaySource` returned `VideoImageSource` only for ChatBox / WebSource / MediaSource /
AlertBox. The scoreboard's frame was rendered and published, then never displayed.
- the preview's Image has a per-type Visibility trigger for each of those and none for IsScoreboard,
so even a correct DisplaySource would have stayed collapsed.
Both are fixed, and the layer test now pins the frame-source list AND the trigger so the pair cannot
drift apart again.
Dev-only affordances are ORANGE from now on (creator ruling): "Simulate (dev)" is a TextBlock in
Brush.Attention, so a development control can never be mistaken for product. The panel test pins the
colour.
gramps
8caee21b9a