Adds 'Copy relative path' to the workspace file-tree context menu + preview header. Folded in gate fixes: preview-header button folds to icon-only on a narrow pane via @container rightpanel (not viewport @media), with data-i18n-title/aria-label so the tooltip+accessible name localize. Full gate: Codex SAFE, Fable SHIP-UX, suite 12147/0, browser clean.
Co-authored-by: Rod Boev <rod.boev@gmail.com>
