Contextual Task Bar: drag it by its handle, pin and reset its position

The grip at the bar's left end now drags the bar anywhere on the canvas
(grab cursor), which always holds it whole, also when the window shrinks.
Unpinned, the bar keeps that offset as it follows the selection (in the
document it was moved in); the "…" button opens a More Options menu with
Hide Bar, Pin Bar Position (checked while pinned: the bar stays where it
is across selection changes and the handle still moves it; unpinned it
follows the selection again from there), Reset Bar Position (unpinned,
back under the selection) and Show Properties Panel, as in Illustrator.
As there, the position and the pin last for the session only.

- UI commands window.taskBar.pin {pinned?} and window.taskBar.reset, so
  the control channel and MCP reach them; ui.inspect reports taskBar
  {pinned, rect}.
- One opt_bool helper reads the {key?: bool} params of the toggling window
  commands (toolbarColumns, floatTools, collapseDock, taskBar.pin).
- New strings in ja, es, zh-hans, zh-hant, pt-br and cs; the dropped
  "Hide Contextual Task Bar" tooltip and per-key es messages removed.
- Headless egui test: dragging the grip moves the bar, the offset follows
  the selection, pin holds it across selection changes and a shrinking
  window, unpin follows from there, reset restores.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

docs/control-protocol.md

@@ -18,7 +18,7 @@ so only enable it while you use it. Transport: `apps/vectorcraft/src/control_ser
 | `engine.execute` | `{command, params}` | run any engine or UI command (see `engine.commands`) |
 | `engine.commands` | | every command with label, shortcut, params doc, enablement |
 | `document.inspect` | `{depth?, childLimit?}` | layer tree, selection, history, paint defaults; the options slice the layer tree as `document.node {summary: true}` does |
-| `ui.inspect` | | tool, UI state, `screenMode` (0 normal, 1 full screen with menu bar, 2 full screen, 3 Presentation Mode), view, canvas rect, window size, perf, background saves and exports still running |
+| `ui.inspect` | | tool, UI state, `screenMode` (0 normal, 1 full screen with menu bar, 2 full screen, 3 Presentation Mode), `taskBar` (`pinned`, and `rect` `[x, y, w, h]` while the Contextual Task Bar shows), view, canvas rect, window size, perf, background saves and exports still running |
 | `ui.menu.list` / `ui.menu.invoke` | `{command, params}` | the full menu tree / invoke an item |
 | `ui.contextMenu.list` | | the canvas context menu for the current selection, flattened like `ui.menu.list` (`path` holds its submenus). `ui.click {x, y, button: "right"}` on the canvas opens it, after selecting the object there unless it is already selected |
 | `ui.tool.select` / `ui.tool.list` | `{tool}` | |
@@ -205,6 +205,15 @@ that open its flyout raise the strip instead. The strips (`ui.floating_flyouts`
 and the strip's top-left corner) are saved with the preferences and in user workspaces; the built-in workspaces
 float none.
 
+The Contextual Task Bar: its handle (the grip at its left end) drags it anywhere on the canvas, which always holds
+it whole, also when the window shrinks. Unpinned, the bar keeps that offset as it follows the selection, until
+another document becomes active. Its More Options (…) menu has Hide Bar (`window.taskBar`); Pin Bar Position
+(`window.taskBar.pin {pinned?}`, omitted toggles, checked while pinned), which holds the bar where it is across
+selection changes (the handle still moves it) and, turned off, lets it follow the selection again from there; Reset
+Bar Position (`window.taskBar.reset`), which unpins it and puts it back under the selection; and Show Properties
+Panel. As in Illustrator, neither the position nor the pin is saved: each launch starts with the bar under the
+selection.
+
 Flatten Transparency: `ui.flattenTransparencyDialog` opens the `flattenTransparency` dialog for the selection
 (fields `preset`: a preset name, setting it loads that preset's options; the option keys of
 `object.flattenTransparency`: `balance` 0–100, `lineArtPpi` and `gradientPpi` 1–2400, `textToOutlines`,