[TASK] CD: Provide a keyboard path for moving items between folders

Parent

Follow-up from #32591 / PR #37436 (Content Drive keybindings).

Problem

Moving items between folders in Content Drive is pointer-only. It is a drag from a listing row
onto a tree node, and there is no keyboard equivalent — no "Move to…" in the context menu that a
keyboard user can reach, no cut/paste pair.

#37436 made the listing keyboard-operable end to end: a roving tab stop reaches it, arrows walk it,
Shift + Arrow builds a range, and Escape backs out. A user can now select exactly the items they
want without a mouse and then has nowhere to go with them. That is the accessibility gap the
keyboard work made visible rather than one it introduced.

What "done" looks like

A keyboard-reachable path from a selection to a destination folder. Options, roughly in order of
cost:

• a "Move to…" entry in the row context menu (the menu is already keyboard-reachable via the
  context-menu key) opening the existing folder picker
• a cut/paste pair scoped to the listing
• arrow-key navigation of the sidebar tree with an explicit "move selection here" action

Whichever is chosen must announce the outcome, not only perform it.

Where

• core-web/libs/ui/src/lib/components/dot-folder-list-view/
• core-web/libs/portlets/dot-content-drive/portlet/
• Shortcut registry, if a combination is wanted:
  core-web/libs/ui/src/lib/services/dot-keyboard-shortcut/ — see
  docs/frontend/KEYBOARD_SHORTCUTS.md

Start in core-web/libs/ui/src/lib/components/dot-folder-list-view/ and core-web/libs/portlets/dot-content-drive/portlet/; trace how keyboard selection and the existing folder picker are wired. Review docs/frontend/KEYBOARD_SHORTCUTS.md and the shortcut registry if a shortcut is considered. Done means a keyboard-reachable move path exists and announces its outcome.