- FindContentBounds scans the Bgra32 capture for the bounding box of non-transparent pixels
(background is injected transparent, so alpha = widget extent). Crop to that rect + Stretch=Fill
maps the widget flush under the selection box: full-canvas widgets fall through to the full frame
(identical to the confirmed-good image); floating widgets get tight-fitted with no dead space.
- Removes QueryContentBoundsAsync + the JS script entirely — the DOM-union attempt (a5b9952) broke
rendering by measuring an unsettled layout on NavigationCompleted; alpha measurement is immune.
- 3 new unit tests: tight box, no-alpha no-crop, full-alpha no-crop. 7/7 pass, 0 warnings.
Bundle exception (2026-08-27): this lands prior-session work plus today's
transparency fix as one commit per creator instruction.
WebView2Manager (new): off-screen WebView2 control parked at -5000/-5000 in
the window's visual tree, captures via CapturePreviewAsync every 100 ms into
a BGRA8 VideoFrame. Source Width/Height sync to the control via
PropertyChanged. JS transparent-background injection runs on every
NavigationStarting/NavigationCompleted so the page's own CSS does not paint
white over the capture.
Transparency fix: DefaultBackgroundColor = System.Drawing.Color.Transparent
set on the WPF control before EnsureCoreWebView2Async. The WPF SDK doc says
the value is forwarded to the controller on init; the IDL (ICoreWebView2-
Controller2) confirms alpha=0 makes the capture alpha-preserving. The
prior-session 'CoreWebView2.BackgroundColor' path was the wrong property
name and has been replaced.
LayoutStore: WebUri column added (idempotent ALTER TABLE) and round-tripped
on save/load (schema v11).
MainViewModel: WebView2Manager constructed on Loaded; loaded web sources
re-registered; Source.WebUri PropertyChanged forwards to manager.
MainWindow: off-screen host Canvas added to visual tree.
Tests: 3 scale-sync + WebView2_DefaultBackgroundColor_Is_Transparent +
LayoutStorePersistenceTests.WebSource_WebUri_Persists. 234/236 pass
(2 pre-existing failures unchanged).
Scale bug (DPI/physical-pixel mismatch) still open.