feat(ui): add right-click close menu for context panel tabs (#3217)

Resolves openchamber/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

packages/vscode/CHANGELOG.md

@@ -16,6 +16,7 @@
 - Updating OpenCode no longer fails with a bare "Bad Request": the extension names the release to install and shows OpenCode's own reason when an update is refused (thanks to @mdatsev and @yulia-ivashko).
 - "Add Project" now adds the chosen folder to the workspace instead of failing (thanks to @bashrusakh), and the extension starts in the current workspace folder instead of one restored from storage (thanks to @makeittech).
 - Multi-Run groups can now contain more than five models (thanks to @tomzx).
+- Right-click an editor, chat, or browser tab in the context panel to close it, close others, close left/right, or close all (thanks to @adavila0703).
 - Sidebar: pending permission and question badges are no longer covered by the hover actions (thanks to @makeittech); worktree branch search hides non-matching branches (thanks to @bashrusakh).
 - Settings: number fields and selects no longer clip at large font sizes (thanks to @makeittech), and Windows skill paths are classified correctly, so disabled and duplicate skills are hidden as intended (thanks to @Ttungx).
 - Windows: closing VS Code now stops the managed OpenCode process instead of leaving it running (thanks to @a0000001).