c9fd1bdaaa
LeftPanel.xaml(.cs) takes the Row 1 Col 0 panel (layers + properties editor and the live chat list). All property-editor/chat handlers moved into the control (SourceNameBox edit, AddSourceButton menu, chat autoscroll self-subscribed on Loaded, mirror/clip-shape, remove-source, background capture change/refresh, opacity slider label, list drag-to-reorder, snapshot revert/accept family). Window keeps only shell + routing: ctor wiring (_leftPanel), geometry, hotkeys, taskbar overlay, BackToAbout, Window_PreviewMouseLeftButtonDown (uses _leftPanel.IsClickInside), UpdateSelectionOverlay (calls _leftPanel.OnSelectionChanged). Zero behavior change; build 0 warnings; 246 pass, only the 2 known failures. Docs: ViewModels/index.md Phase 2 tracker updated in same commit.