fix(i18n): add time format translations to all 13 missing locales

Also translate server error message to English and remove stale
comment from calendar.js catch block.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

public/locales/sv.json

@@ -607,6 +607,9 @@
     "dateFormatLabel": "Önskat datumformat",
     "dateFormatHint": "Välj hur datum visas i appen.",
     "dateFormatSavedToast": "Datumformat sparat.",
+    "timeFormatLabel": "Tidsformat",
+    "timeFormatHours": "timmar",
+    "timeFormatSavedToast": "Tidsformat sparat.",
     "themeSystem": "System",
     "themeSysLabel": "Använd systeminställning",
     "themeLight": "Ljus",