feat(ui): move export/import features from board header to project settings

Relocate the export and import features functionality from the board header
dropdown menu to a new "Data" section in project settings for better UX.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/ui/src/components/views/project-settings-view/hooks/use-project-settings-view.ts

@@ -1,6 +1,12 @@
 import { useState, useCallback } from 'react';
 
-export type ProjectSettingsViewId = 'identity' | 'theme' | 'worktrees' | 'claude' | 'danger';
+export type ProjectSettingsViewId =
+  | 'identity'
+  | 'theme'
+  | 'worktrees'
+  | 'claude'
+  | 'data'
+  | 'danger';
 
 interface UseProjectSettingsViewOptions {
   initialView?: ProjectSettingsViewId;