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/pages/SettingsPage.jsx

@@ -16,12 +16,14 @@ import {Skeleton} from '@/components/ui/skeleton';
 import {Switch} from '@/components/ui/switch';
 import FormField from '../components/FormField.jsx';
 import SteamAccountCard from '../components/SteamAccountCard.jsx';
+import ProfileStatsSettings from '../components/stats/ProfileStatsSettings.jsx';
 import {settingsSchema} from '../utils/validation.js';
 import {usePreferences} from '../context/PreferencesContext.jsx';
 import useSessionExpired from '../hooks/useSessionExpired.js';
 import useSaveAppearance from '../hooks/useSaveAppearance.js';
 import {ACCENTS, CORNERS} from '../utils/appearance.js';
 import {coverUrl} from '../utils/games.js';
+import {saveProfileStats} from '../utils/stats.js';
 import {cn} from '@/lib/utils';
 import {apiFetch, refreshSession} from '../utils/api.js';
 import {hasSession, markSession} from '../utils/auth.js';
@@ -59,6 +61,7 @@ export default function SettingsPage() {
     const [profile, setProfile] = useState(null);
     const [isLoading, setIsLoading] = useState(true);
     const [loadError, setLoadError] = useState(null);
+    const [savingProfileStats, setSavingProfileStats] = useState(false);
     const [searchParams, setSearchParams] = useSearchParams();
     // Read once: removing the parameter below must not load the profile again.
     const [steamOutcome] = useState(() => searchParams.get('steam'));
@@ -197,6 +200,31 @@ export default function SettingsPage() {
         }
     };
 
+    // Shown at once; the switches wait for the answer, so the saves reach Auth one after the other.
+    const handleProfileStatsChange = async (groups) => {
+        const previous = profile?.settings?.profileStats ?? [];
+        const showProfileStats = (next) => setProfile((p) => ({...p, settings: {...p.settings, profileStats: next}}));
+        showProfileStats(groups);
+        setSavingProfileStats(true);
+        try {
+            const response = await saveProfileStats(groups);
+            if (response.status === 401) {
+                expireSession();
+                return;
+            }
+            if (!response.ok) {
+                showProfileStats(previous);
+                toast.error(t('SETTINGS.ERROR_SAVE'));
+            }
+        } catch (err) {
+            console.error('Profile stats save error:', err);
+            showProfileStats(previous);
+            toast.error(t('INFO.ERROR.NETWORK_FAILURE'));
+        } finally {
+            setSavingProfileStats(false);
+        }
+    };
+
     const copyProfileLink = async (link) => {
         try {
             await navigator.clipboard.writeText(link);
@@ -429,6 +457,9 @@ export default function SettingsPage() {
                                 </Button>
                             </div>
                         )}
+                        <ProfileStatsSettings selected={profile?.settings?.profileStats ?? []}
+                                              disabled={!publicProfile} saving={savingProfileStats}
+                                              onChange={handleProfileStatsChange}/>
                     </div>
                 </CardContent>
             </Card>