Selecting a Scoreboard layer now shows its settings, using the app's own widgets only:
- eight fact checkboxes (subscribers, watch hours, Super Chats, new members, milestones, last member,
last Super Chat, last gift)
- text colour and plate colour via YtComboBox over BorderColorPalette (the app's one palette —
TASK 63's rule: a picker IS the app's drop-down, never a hand-built menu)
- plate on/off, plate opacity, text size 14-24
Every change pushes through the presenter (SetStyle/SetTiles) and repaints the strip, so the preview
and the output follow immediately. One look per layout, stored on the view-model: the scoreboard is a
single billboard, not eight independent widgets.
Guard: ScoreboardPropertiesTests asserts the panel is gated on SelectedElement.IsScoreboard, binds
all eight facts and the four look controls, uses YtComboBox/YtCheckBox only, and that the VM surface
exists for each name (a typo would otherwise bind to nothing in silence).
Adds SourceType.Scoreboard with the same per-scene eye toggle, drag and presence as every other
element — 'prominent on BRB, dialled back on Live' is geometry, not a second mechanism. Default
geometry is the strip: 1920 wide, 56 tall, bottom edge.
The output resolver returns the presenter's cached frame exactly like the chat box and alert box do,
and every session start clears the tallies. Preview publication writes one shared WriteableBitmap on
the UI thread (the pump thread must never touch one), refreshed only when a displayed value moves.
Guard: ScoreboardLayerTests pins the enum member, the geometry constants, the resolver case and the
session hook, so the layer cannot quietly become a special widget.
gramps