Contextual Task Bar: the Fill and Stroke chips show the proxies' paints

The chips drew the first selected object's fill and stroke. They now show
the paints the Fill and Stroke proxies show, a group's painted art
included, and a "?" when the selected objects' paints differ. A click on
either chip shows the Swatches panel through `window.panel.activate`, so
it also appears when the panel is floating, closed or in an expanded dock
column; an open flyout stays open. The progress doc describes the
reference app's bar in its own words.

docs/target-app-parity.md

@@ -560,8 +560,8 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
   - With one image selected, the contextual task bar offers Image Trace, which traces the image at once with the Default preset (the Image Trace panel is left as it was), and Crop Image; with an Image Trace object it offers Expand, which keeps only the traced paths. This follows Illustrator's bar: for a selected image it includes Image Trace, Retype and Crop Image, and traced artwork can be expanded from it ([Contextual Task Bar announcement](https://community.adobe.com/announcements-651/contextual-task-bar-in-illustrator-2025-quick-actions-when-you-need-them-1546580)). Offset Path and Simplify, which don't apply to an image, aren't offered for one. Not done: Retype, which the app doesn't have.
   - With the Artboard tool, the contextual task bar sits under the selected artboards and offers Resize (Artboard Options for the active artboard), Duplicate (each selected artboard, in one undo step, the copies then selected), Rearrange All (with two or more artboards) and Export (Export for Screens with the selected artboards checked). This follows Illustrator's bar: while the Artboard tool is in use, it has options for resizing, duplicating and exporting artboards (the [Contextual Task Bar announcement](https://community.adobe.com/questions-652/contextual-task-bar-in-illustrator-2025-quick-actions-when-you-need-them-1546580); Rearrange and Export on the bar: [Managing Artboards in Illustrator](https://creativepro.com/managing-artboards-in-illustrator/)).
   - The contextual task bar offers more next steps by selection (<https://helpx.adobe.com/illustrator/desktop/get-started/learn-the-basics/contextual-task-bar-overview.html>): an open path Join and Edit Path (the Direct Selection tool), a closed path Edit Path, a compound path Edit Path and Release Compound Path, a clipping group Edit Clipping Path and Release Clipping Mask instead of Ungroup and Isolate, an image selected with vector art Make Clipping Mask instead of Unite, and point or area type Convert To Area Type or Convert To Point Type beside Create Outlines. Evidence: `crates/ui-egui/src/tests/taskbar.rs`.
-  - The contextual task bar has a Stroke chip beside the Fill chip, drawn with the selected object's stroke paint; a click brings the Stroke proxy forward and opens the Swatches panel, as a click on the Fill chip does for the Fill proxy ("Fill and Stroke to change the colors": [Contextual Task Bar overview](https://helpx.adobe.com/illustrator/desktop/get-started/learn-the-basics/contextual-task-bar-overview.html)). Evidence: `the_task_bar_shows_a_stroke_chip_beside_fill` in `crates/ui-egui/src/canvas/tests.rs`.
-  - With anchor points selected with Direct Selection, the contextual task bar offers Remove Anchor Points, Connect (`path.join`), Cut Path, Corner and Smooth (`path.convertAnchors` with `to` set to `corner` or `smooth`), the commands of the Control bar's anchor buttons. As in Illustrator ("Remove selected anchor points, Connect selected end points, Cut path at selected anchor points, Convert selected anchor points to corner, and Convert selected anchor points to smooth": [Contextual Task Bar overview](https://helpx.adobe.com/illustrator/desktop/get-started/learn-the-basics/contextual-task-bar-overview.html)). Not done: Simplify, which the bar offers only while no anchors are selected, and the bar's Smooth item that adjusts a path's curvature, a command the app doesn't have (Object › Path › Smooth).
+  - The contextual task bar has a Stroke chip beside the Fill chip, drawn with the paint the Stroke proxy shows (a "?" when the selected objects' strokes differ, as on the Fill chip); a click brings the Stroke proxy forward and shows the Swatches panel wherever it is docked, floating or closed, as a click on the Fill chip does for the Fill proxy. The reference app's bar has Fill and Stroke controls for changing an object's colors ([Contextual Task Bar overview](https://helpx.adobe.com/illustrator/desktop/get-started/learn-the-basics/contextual-task-bar-overview.html)). Evidence: `the_task_bar_shows_a_stroke_chip_beside_fill` and `the_task_bar_chips_follow_the_proxies_and_show_swatches_anywhere` in `crates/ui-egui/src/canvas/tests.rs`.
+  - With anchor points selected with Direct Selection, the contextual task bar offers Remove Anchor Points, Connect (`path.join`), Cut Path, Corner and Smooth (`path.convertAnchors` with `to` set to `corner` or `smooth`), the commands of the Control bar's anchor buttons. As in Illustrator, whose bar has items that delete the selected anchors, join selected end points, split the path at the selected anchors, and make the selected anchors corner or smooth points ([Contextual Task Bar overview](https://helpx.adobe.com/illustrator/desktop/get-started/learn-the-basics/contextual-task-bar-overview.html)). Not done: Simplify, which the bar offers only while no anchors are selected, and the bar's Smooth item that adjusts a path's curvature, a command the app doesn't have (Object › Path › Smooth).
   - Tool flyouts tear off: dragging or clicking the tear-off bar on a flyout's right side (or releasing the long press over it) floats its group as a strip of tool buttons, moved by the same bar and put back in the toolbar by the × at its top (`window.floatTools`). While a group floats, the presses that would open its flyout raise the strip instead. Floating strips are kept with the preferences and in user workspaces. Not done: turning a strip vertical, docking it.
   - Screen readers get a name for the Tools panel's tool buttons, flyout rows, floating strips and tear-off bars, and for the icon buttons, text buttons, toggles, checkboxes, radio buttons, tabs, chips, sliders, angle dials and combo boxes that panels and dialogs draw with `crates/ui-egui/src/widgets.rs`: the text, label or tool tip each one shows, or a name of its own where it shows none (the angle dial, the spinner, the preset arrow, the color wheel and the Reference Point's squares). The tool buttons, toggles, checkboxes, radio buttons, tabs and the Reference Point's nine squares also report whether they are on, an icon button that is lit, such as the chosen Align To button, reports that it is pressed, and the angle dial reports its angle. The status bar's First, Previous, Next and Last Artboard buttons have tool tips.
   - These dialog sliders, each beside a number field, respond to the keyboard: those of the effect, tool option, brush and transform dialogs, the Perspective Grid, the 3D dialogs, and the flattener options, which the Flattener Preview panel also shows. A click, or Tab, gives a slider the keyboard focus, and an outline shows it. Then → and ↑ step the field's number up to the next whole number and ← and ↓ step it down to the next whole number, Shift with an arrow and Page Up and Page Down step it by ten, and Home and End set the slider's first and last value; no step goes past either end. Screen readers' increment and decrement actions step the slider as → and ← do. The Color panel's, Swatch Options', the Navigator's and the Character panel's sliders, and the Color Picker's channel slider, respond only to the pointer. The keys follow the WAI-ARIA slider pattern (<https://www.w3.org/WAI/ARIA/apg/patterns/slider/>); the reference app's help does not describe keys on a dialog's slider, so the step sizes are VectorCraft's own.