Accessibility: buttons, toggles, checkboxes and sliders have names for screen readers

The controls that the shared widgets draw had no name in the
accessibility tree: icon, flat, primary, secondary and split buttons,
chips, toggles, checkboxes, radio buttons, tabs, sliders, the angle
dial, the Reference Point's squares, the spinner and preset arrows and
the searchable combo boxes. Screen readers announced each clickable one
as an unnamed element of unknown role, and a disabled icon button was
not in the tree. The Color Guide's library button, the Color Themes
Save button and the status bar's artboard buttons also had no name.

Each helper in widgets.rs except color_field now gives its response a
role, a name and its state. The name is the text, label or translated
tool tip the helper shows. The spinner, the preset arrow, the angle
dial, the harmony wheel and the Reference Point's squares, which show
none, are named "Step up or down", "Presets", "Angle", "Color wheel"
and Top Left to Bottom Right. A toggle, checkbox, radio button, tab or
Reference Point square reports whether it is on, an icon button reports
that it is pressed while it is lit, the angle dial reports its angle,
and a searchable combo box reports the text it shows. A checkbox or
radio button drawn without text is named by the label beside it. The
Tools panel's tool buttons, flyout rows and floating strips are named
by their tools' tool tips, with the active tool pressed. The title
bar's column toggle, the tear-off bars, a floating strip's close box
and the Color, Gradient and None buttons are named by their tool tips.

The status bar's First, Previous, Next and Last Artboard buttons now
have tool tips, and the Fill and Stroke chips' tool tips are
translated. The six new strings (the four artboard tips, "Color wheel"
and "Step up or down") have rows in every catalog.

split_button, chip_button, color_slider, channel_slider and the dialog
form's slider_field and slider_rail keep their arguments. New _named
variants beside them take the arrow's tool tip, the chip's tool tip or
the slider's name, and every caller in the tree uses them.

Docs: docs/target-app-parity.md.

docs/target-app-parity.md

@@ -431,6 +431,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
   - The contextual task bar's handle drags it anywhere on the canvas (kept whole on it as the window resizes); unpinned it keeps that offset as it follows the selection, and its More Options menu hides it, pins its position across selection changes (`window.taskBar.pin`), resets it under the selection (`window.taskBar.reset`) and shows the Properties panel. As in Illustrator the position isn't kept across launches. Not done: the bar's tool-specific variants (only the selection tools show it).
   - 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. As in Illustrator ("Selecting images displays options like Image Trace, Retype, and Crop Image"; "You can also quickly expand traced artwork from the bar": [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.
   - 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.
   - Panels undock (#495): a dock tab, a panel icon or a popped-out panel's title dragged out of the dock floats that panel inside the window, and the strip right of the dock's tabs floats the whole tabbed group. A floating group moves by its title bar, a tab dragged out of it floats on its own, and dropped on another group's title bar or tabs it stacks with that group; dropped on the dock, which lights up under the pointer, its panels go back where they live (the tabbed group or the icon column), as its × and the panel menus' Float Panel / Dock Panel do (`window.panel.float`, `window.panel.dock`). The Tools panel floats by its title bar and docks again on the window's left edge. Floating groups stack into sets: dropped on the upper or lower half of another group (a line shows where), a group joins it right above or below it, and the set's groups stack top to bottom, each showing one panel, moving together by the top group's title bar, whose × docks them all; a group dragged by its tab strip leaves the set (`window.panel.float {below, above}`). A double-click on a tab collapses a floating group to its tabs (`collapsed`). Sets dropped on the left edge of the icon column or of another dock column dock as dock columns (a multi-column dock, `window.panel.dock {column}`), whose groups stack, tab and tear out as a floating set's do, and whose top strip floats the column again. Floating panels, their sets and the Tools panel's position are kept with the preferences and in user workspaces, and clamped into a smaller window. Not done: panels in separate OS windows, docking a panel into the default tabbed group it doesn't belong to, reordering tabs by dragging, collapsing a set or dock column to icons, dock columns right of the default dock, resizing floating panels and the groups of a set.
   - The dock's double arrow collapses Properties, Layers and Libraries to icons at the top of the icon column, popping out like the other icon panels, and expands them again (`window.collapseDock`, kept with the preferences and in saved workspaces). The icon column's own arrow (expanding the icon panels into a full column) is not done.
   - Czech render-site labels: desktop/web file filters, diagnostics, suggested preset names and contributor tooltips/plurals now use catalog lookups; gradients have Czech adjective agreement and printer marks have a separate context (PDF/Print and Summary). Search, Home, toolbar/panel tooltips and Preferences already look up their labels; new variable keys fall back to English in other languages. Evidence: `i18n::tests::czech_render_site_follow_up`, `dialogs::tests_modal::printer_mark_labels_are_distinct_from_language_names`; see [localization-parity.md](localization-parity.md).