Resolvesopenchamber/openchamber#3123.
The right panel's tab strip (browser, files, chat, and other
multi-instance surfaces) now supports a right-click context menu with
Close, Close others, Close to the left, Close to the right, and Close
all. These act on the current surface's tabs and reuse the new bulk
close action, so closing the active surface's last tab still closes the
panel while other surfaces remain.
- Add closeContextPanelTabs(directory, ids) to useUIStore
- Add opt-in tabContextMenu prop to SortableTabsStrip (no impact on other consumers)
- Wire the menu in ContextPanel with full i18n coverage across 11 locales
- Cover the bulk close with store tests