# HANDOFF — 2026-10-07

## Branch
- main (no feature branch)

## Dirty files
- None (zoom box fix + test committed as a work unit this session).

## What just happened
- Fixed the zoom box: right-click in live preview now procs the selected Zoom View
  Shape with correct anchoring and a visible, populated box (previously invisible —
  empty OpacityMask made the whole box transparent and the VisualBrush pointed at the
  CanvasGrid *ancestor*, a circular reference WPF renders as nothing).
- Zoom View Shape dropdown now uses the app's standard `YtComboBox` style.
- One integration test added (Good Dog Rule): `ZoomBoxInteractionTests` — circle is a
  centered square, phone is a tall 9:16 rect and tablet a wide 16:9 rect, both anchored
  top-left at the click, box stays inside 1920x1080 (clamp), and the UI shows the right
  outline/clip per shape. Full suite: 404 passed, 0 warnings.

## Zoom feature state
- Models/ZoomState.cs + Models/ZoomShape.cs (Circle, VerticalRectangle, HorizontalRectangle)
- ViewModel: zoom box activation/move/dismiss; compositor output crops+scales the zoom region; dimming updates
- PreviewPane: zoom box is a *sibling* of CanvasGrid inside a new `PreviewCanvas` wrapper
  (so the VisualBrush can sample CanvasGrid without a circular reference); shape-aware
  outline (`ZoomRectOutline`/`ZoomCircleOutline`) + ellipse clip for Circle
- Shape semantics in `MainViewModel.ActivateZoom`: Circle = click point is center, w=h=min(maxW,maxH);
  VerticalRectangle = 9:16 tall, HorizontalRectangle = 16:9 wide, both anchored top-left at the click; clamped to frame
- Settings (OverlayHost) Zoom View Shape persisted via LayoutStore

## Known issues / follow-ups
- Background toggle bug mentioned earlier: when clicking "Use default background" in layer properties, nothing happens. Need to investigate - binding exists (UseDefaultBackground), VM has handler that invalidates bake and updates. May need to look up Source background logic.

## Next step
- User runs the app live/test to eyeball the zoom box visuals (border shows, region content visible,
  circle is round, phone/tablet anchored at the click point). Then background "Use default background"
  toggle if still needed. Otherwise stand down.