Drawing toolbar redesigned to match the app's toolbar language: tools now sit in
brush / shape / eraser clusters split by hairline dividers, with the same subtle
elevated-fill active state as the main toolbar (no more heavy solid-accent blocks).
Refined colour row — swatches gain a neutral selected-ring with a surface gap (legible
on light, dark, and the white swatch), plus a new custom-colour well (rainbow gradient
that opens the native picker) at the end.
Flyouts unified & cleaned up. The Shapes picker and the Text/Media group pop-ups now
share one FlyoutPanel shell and render as a single tidy icon-only row (tooltips via
title), replacing the boxed captioned tile-grids.
Group buttons are now a segmented control — an icon half (runs the last-used tool) and
a slim caret half (opens the picker) that light up together, replacing the corner-caret.
Fixed
Drawing toolbar now sits at the bottom, centered directly above the main toolbar (it
was pinned to the top of the page) — the same slot the tool flyouts open into.
Flyout positioning now adapts to menu width. The small Text/Media pickers anchor
directly above their own toolbar button; the wide Shapes/Data picker stays centered over
the whole toolbar (like the draw bar) so it doesn't run off-screen.
Flyouts are now actually centered on their anchor. The panel's translateX(-50%)
was being clobbered by motion's animated transform, so panels anchored by their left
edge and sat off to the right. Positioning now lives on a separate wrapper from the
entry animation.
