fix: first native launch since refactor crashed — 3 stacked faults, all closed; RoundClip 'known failure' root-caused and green

User launch (2026-09-01 19:07) NRE'd in MainViewModel ctor:
1. SceneGraph (TASK 31) was 'null!'-declared, assigned mid-ctor, but Scenes is touched
   ~120 lines earlier — field-initialized now.
2. LeftPanel extraction (c9fd1bd) moved StaticResource users (EyeButton/EyeIconStyle)
   into a UserControl while the styles stayed window-scope — invisible at parse time;
   moved to Themes/Controls.xaml (app scope, the existing rule). Full audit: these were
   the only two offenders (grep of Controls/*.xaml StaticResource keys vs app dictionary).
3. RoundClipInteractionTests — the second 'known failure' the map never explained: it
   was two stale-test layers (window.FindName across the new UserControl namescope +
   VisualTreeHelper.HitTest, which returned the IsHitTestVisible=False WebViewHostPanel
   overlay for EVERY point; UIElement.InputHitTest — the real input pipeline — shows the
   corner IS grabbable in both Traditional and Round). Test fixed, no product bug.
Verified: clean rebuild 0 warnings; app boots (log shows full MainWindow loaded; user
clicked + closed, zero new exceptions; real DB Webcam row = the genuine C920, untouched);
RoundClip + 6 RealApp classes pass natively per-class.
Docs: ai.md known-failure note → 246/247 (audio only); TASK 31 verification paragraph
corrected ('cannot run headless' overstated — per-class Windows-host vstest runs them);
MyMistakes: InputHitTest-vs-VTH recipe + namescope/app-style + shared-log facts.
Spin-guard citations: WPF Visual Tree Overview (InputHitTest vs VisualTreeHelper hit
semantics) + XAML namescope docs, learn.microsoft.com.

TASKS.md

@@ -1311,8 +1311,16 @@ What landed — core optimization + SceneGraph component, all in one commit:
 
 **Verification:** SceneCompositorTests 4, StretchMathTests 4, BackgroundTests 16, SceneCatalogTests 18,
 LayoutStorePersistenceTests 12, FramePumpTests 9, SceneGraphTests 1 all green. RealAppHost GUI/collection
-tests (SourceNaming, RoundClip, BackgroundHeal, ...) construct a real `MainWindow` and cannot run in a
-headless WSL session (pre-existing limitation, not caused by this change).
+tests (SourceNaming, RoundClip, BackgroundHeal, ...) construct a real `MainWindow` — **CORRECTED
+2026-09-01:** they DO run from WSL when invoked per-class through the Windows `dotnet.exe` vstest host
+(the old "cannot run headless" claim conflated them with the full-suite WASAPI hang). Two first-launch
+crashes this refactor shipped with were caught on the first real native launch and fixed same day:
+ctor-order `SceneGraph` NRE (`null!` field assigned after first ctor use — now field-initialized) and
+window-scope `EyeButton`/`EyeIconStyle` consumed via `StaticResource` from the extracted `LeftPanel`
+(UserControl namescopes can't see window resources — styles moved to `Themes/Controls.xaml`, the
+app-scope rule honored). The RoundClip "known failure" was then root-caused to stale test code
+(`window.FindName` across namescopes + `VisualTreeHelper.HitTest` where `UIElement.InputHitTest`
+models input) — test green 2026-09-01, the sole remaining known failure is the audio one.
 
 ### Design