fix(firms): label a snapshot that ends at a set time with that time, not LIVE

A FIRMS source may answer the 24 hours to a set time, naming its end as
`at` (epoch ms). The layer row then reads "24 h to MM-DD HH:MM UTC"
instead of "LIVE · updated ...", and getStats() reports `at`. A
snapshot without `at` (the trailing 24 hours to now, as the dev proxy
serves) keeps the LIVE label. Translated in every catalog.

src/i18n/locales/de.json

@@ -164,6 +164,7 @@
   "loading...": "lädt...",
   "KEY REQUIRED": "SCHLÜSSEL ERFORDERLICH",
   "LIVE · updated {age}": "LIVE · aktualisiert {age}",
+  "24 h to {day} {time} UTC": "24 Std. bis {day} {time} UTC",
   "loading mapped installation context": "Kontext der kartierten Anlage wird geladen",
   "MAPPED INSTALLATION": "KARTIERTE ANLAGE",
   "LAUNCH SITE · {site}": "STARTPLATZ · {site}",