Changelog

Replace compiled binding cast syntax ((vm:TasksViewModel)DataContext)

with reflection binding fallback $parent[UserControl].DataContext inside

DataTemplate — the cast syntax can't resolve plugin types at runtime

within a template context.

Root cause: the ListBox in flat sub-mode was wrapped in a redundant

outer ScrollViewer that offered infinite horizontal width during

measure, bypassing the pixel-constrained Grid column width. Since

ListBox already has its own internal ScrollViewer for vertical

scrolling, the outer one was unnecessary and broke width constraint

propagation.

• Remove redundant outer ScrollViewer around flat sub-mode ListBox,

move IsVisible binding to ListBox directly

• Add HorizontalScrollBarVisibility="Disabled" to GTD and Calendar

sub-mode ScrollViewers (these use ItemsControl which has no built-in

scroll, so the outer ScrollViewer is needed but must not offer

unconstrained horizontal space)

The SplitPaneLayout custom Control wasn't constraining content width

properly — items expanded beyond pane bounds regardless of Clip,

ClipToBounds, or measure constraints.

Replaced with a standard Grid where ColumnDefinitions start as star

(*) sizing for initial layout, then get switched to pixel-based

GridLength values in OnLoaded + SizeChanged. Pixel-based columns

give the Grid's layout engine an exact width budget for each column,

and content is properly constrained. ClipToBounds on each pane

handles any remaining overflow.

The resize handle, drag interaction, and ratio persistence all work

through the ColumnDefinition.Width property — no FindControl for

child panels needed.

The block type picker's InsertBlockType() switch statement had no

cases for columns_2, columns_3, or columns_2_wide_left. Selecting

any column layout from the "/" palette or Add Block button silently

did nothing.

Fix: add AddColumnsBlock relay command to NotesViewModel that

delegates to the existing CreateBlockFromTypeId() (which already

handles all three column variants). Wire the three column type IDs

in the picker's switch statement to call the new command.

Cover image action buttons (Change/Reposition/Remove) were positioned

at top-right with Margin="0,44,12,0", placing them directly under the

ToolbarHoverZone (ZIndex=1, Height=120 when cover exists). The hover

zone captured all pointer events before they reached the buttons.

Fix: move buttons to bottom-right of the cover (VerticalAlignment=

Bottom, Margin="0,0,12,28") and set ZIndex=2 so they float above the

toolbar hover zone. Buttons now appear on cover hover and are fully

clickable.