fix: resolve multiple production issues

- Fix archive page showing "00" instead of "0" for empty photo counts
- Fix email queue PostgreSQL "updated_at" column error with migration and fallback
- Fix storage calculation discrepancies between system status and archive pages
- Add proper storage info to system status endpoint
- Fix archive path concatenation in settings endpoint

🤖 Generated with [Claude Code](https://claude.ai/code)

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

frontend/src/pages/admin/ArchivesPage.tsx

@@ -169,7 +169,10 @@ export const ArchivesPage: React.FC = () => {
             <div>
               <p className="text-sm text-neutral-600">{t('archives.totalPhotos')}</p>
               <p className="text-2xl font-bold text-neutral-900">
-                {archives.reduce((sum, a) => sum + (a.photoCount || 0), 0).toLocaleString()}
+                {(() => {
+                  const total = archives.reduce((sum, a) => sum + (parseInt(String(a.photoCount)) || 0), 0);
+                  return total === 0 ? '0' : total.toLocaleString();
+                })()}
               </p>
             </div>
             <FileArchive className="w-8 h-8 text-green-600" />

frontend/src/services/settings.service.ts

@@ -47,6 +47,11 @@ export interface SystemStatus {
       activityLogs: number;
     };
   };
+  storage: {
+    totalUsed: number;
+    photoStorage: number;
+    archiveStorage: number;
+  };
   emailQueue: {
     pending: number;
     sent: number;