Canvas · Panels: layers, inspector, alignment, assets, style and layout editors

LayerPanel lists the canvas's layers topmost first on lists::Tree: a box
shows or hides each, F2 renames, a drag restacks into a new paint order.
InspectorPanel edits the one selected shape's frame, fill, visibility and
lock. AlignmentToolbar lines up or spreads the selection through
`aligned`. AssetPanel finds shapes by name in a picks grid, each drawn
to fit its tile. ColorPanel, ShadowEditor, BorderEditor and
TypographyPanel edit a look; GradientPanel is forms::GradientEditor.
ConstraintsEditor pins a shape to its frame, with `Constraints::placed`;
AutoLayoutControls sets flow, gap, padding and a place grid, with
`AutoLayout::laid`; ExportPanel names each file once. The panels share
`canvas::panel`: editing, pair, caption, heading and color_well.

src/primitives/icon.rs

@@ -39,9 +39,17 @@ icons! {
     Activity => "activity",
     AlarmClock => "alarm-clock",
     AlignCenter => "align-center",
+    AlignCenterHorizontal => "align-center-horizontal",
+    AlignCenterVertical => "align-center-vertical",
+    AlignEndHorizontal => "align-end-horizontal",
+    AlignEndVertical => "align-end-vertical",
+    AlignHorizontalDistributeCenter => "align-horizontal-distribute-center",
     AlignJustify => "align-justify",
     AlignLeft => "align-left",
     AlignRight => "align-right",
+    AlignStartHorizontal => "align-start-horizontal",
+    AlignStartVertical => "align-start-vertical",
+    AlignVerticalDistributeCenter => "align-vertical-distribute-center",
     AppWindow => "app-window",
     Archive => "archive",
     ArrowDownLeft => "arrow-down-left",
@@ -284,8 +292,10 @@ icons! {
     Square => "square",
     SquareFunction => "square-function",
     SquarePen => "square-pen",
+    SquareRoundCorner => "square-round-corner",
     Star => "star",
     StepForward => "step-forward",
+    StickyNote => "sticky-note",
     Strikethrough => "strikethrough",
     Sun => "sun",
     Table => "table",