feat(stats): add stats page and pile trend

Show the stat groups on /stats, the pile trend on the dashboard card,
one switch per group in the settings, and the shared groups on the
public profile.

src/components/AppHeader.jsx

@@ -1,6 +1,6 @@
 import {Link, NavLink, useLocation} from 'react-router-dom';
 import {useTranslation} from 'react-i18next';
-import {Dices, Languages, LayoutDashboard, Library, LogOut, Moon, Settings, Sun} from 'lucide-react';
+import {ChartColumn, Dices, Languages, LayoutDashboard, Library, LogOut, Moon, Settings, Sun} from 'lucide-react';
 
 import {Button} from '@/components/ui/button';
 import {
@@ -22,6 +22,7 @@ const NAV_ITEMS = [
     // The wishlist is a tab of the library.
     {to: '/library', labelKey: 'NAV.LIBRARY', Icon: Library, alsoActiveOn: ['/wishlist']},
     {to: '/play-next', labelKey: 'NAV.PLAY_NEXT', Icon: Dices},
+    {to: '/stats', labelKey: 'NAV.STATS', Icon: ChartColumn},
 ];
 
 const navLinkClass = (isActive) => cn(