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>

backend/src/routes/adminSettings.js

@@ -520,11 +520,15 @@ router.get('/storage/info', adminAuth, async (req, res) => {
 
     let archiveStorage = 0;
     for (const archive of archives) {
-      try {
-        const stats = await fs.stat(archive.archive_path);
-        archiveStorage += stats.size;
-      } catch (error) {
-        console.error('Archive file not found:', archive.archive_path);
+      if (archive.archive_path) {
+        try {
+          const storagePath = process.env.STORAGE_PATH || path.join(__dirname, '../../../storage');
+          const fullArchivePath = path.join(storagePath, archive.archive_path);
+          const stats = await fs.stat(fullArchivePath);
+          archiveStorage += stats.size;
+        } catch (error) {
+          console.error('Archive file not found:', archive.archive_path, error.message);
+        }
       }
     }