Window: a second Tab shows only the bars the first Tab hid

Tab set the panels, the toolbar and the Control bar to one value on
each press. Two presses turned on a Control bar that had been off.
When the toolbar was hidden with Window › Tools, Tab showed the toolbar
and the Control bar instead of hiding the panels.

Tab now records which of the three showed when it hides them, and the
next Tab shows those again. Panels shown with Shift+Tab in between
stay shown. While the panels are hidden and the toolbar or the
Control bar shows, as after Shift+Tab, Tab hides those bars instead of
showing all three. When the toolbar or the Control bar was shown another way
after Tab hid them, the next Tab hides what shows and records that
instead. A switch of workspace clears the record. When none of the
three shows and Tab hid none, Tab shows all three, as before. The
record is saved with the other UI settings, so the first Tab after a
restart shows the same bars.

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

docs/target-app-parity.md

@@ -448,6 +448,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
   - In isolation mode the Control bar has an Exit Isolation Mode button (`object.exitIsolation`), except while a pattern is edited. Outside isolation mode, with one group, compound path, path, image, mesh or placed file selected, it has an Isolate Selected Object button (`object.isolate`), which also isolates a path inside a group that Direct Selection selected.
   - Tab shows and hides the panels (in the Type tool it types a tab) without moving the keyboard focus onto a field, so the next shortcut or letter still works; in dialogs and panel fields it moves between fields.
   - Shift+Tab (`window.panels`) shows and hides the dock and the floating panels and leaves the toolbar and the Control bar as they are; hiding the panels with Tab or Shift+Tab also closes a panel popped out of the icon column.
+  - The second Tab (`window.dock`) shows again only the bars the first Tab hid, after a restart too: a Control bar that was off stays off, a toolbar hidden with Window › Tools stays hidden, and panels shown with Shift+Tab in between stay shown.
   - Cmd/Ctrl+A follows the keyboard: in a panel, dialog or search field it selects the field's text, while the Type tool edits it selects all of that text (also `select.all` over MCP), and only otherwise every object. On macOS the menu bar's Select All, Cut, Copy and Paste (keys or clicks) act on a focused field too, and elsewhere the in-window menus' do: the field that had the keyboard when the menu opened gets them, with its selection, and the keyboard back (#516). Not yet: Select All across threaded frames (one frame's text is selected).
   - Cmd/Ctrl+Alt+Q (`type.resetTracking`) sets the tracking of the selected type, or of the text the Type tool has selected, to 0 and its kerning to Auto (0 in the Character panel), in one undo step; at a caret it resets the kerning of the character before it.
   - Shortcut sets other apps save as text (`.kys`) open in Import Shortcut Set from File › Open, from Edit › Keyboard Shortcuts › Import… in the desktop app, or from a drop on the window. It matches each entry to a tool, command or panel by name and decodes the file's key and modifier codes where VectorCraft's default shortcuts agree on them; the user answers the rest, and Apply fills the Keyboard Shortcuts dialog's working set. The answers are kept with the preferences for the next import (`shortcutSet.read`, `importMatches.*`).