feat: ON AIR status-bar badge + auto-updater UI (10-min check, progress)

ON AIR badge (bottom status bar, shown when live-status publishing is on): a
blinking red light + "On air" when a QSO was logged in the last 5 min, dim
"Offline" otherwise. Seeded at launch from LiveLastQSOAgeSec so it's right
immediately, flips online on qso:logged, expires via a 10s tick.

Auto-updater UI: the update check now also runs every 10 minutes, and the
update notification downloads and installs in-app — a live progress bar
(update:progress) then OpsLog restarts on the new build. Falls back to opening
the release page when there's no auto-download asset or on error (retry).
Regenerated bindings for DownloadAndApplyUpdate / LiveLastQSOAgeSec.

frontend/src/lib/i18n.tsx

@@ -14,6 +14,14 @@ type Dict = Record<string, string>;
 const en: Dict = {
   // Menu bar
   'prop.title': 'Propagation', 'prop.geomag': 'Geomag', 'prop.refresh': 'Refresh space weather',
+  'live.onAir': 'On air', 'live.offline': 'Offline',
+  'live.onAirTip': 'On air — a QSO was logged in the last 5 minutes (published to the live status)',
+  'live.offlineTip': 'Offline — no QSO logged in the last 5 minutes',
+  'upd.available': 'OpsLog v{v} available', 'upd.current': "You're on v{v}.",
+  'upd.install': 'Update now', 'upd.download': 'Download', 'upd.later': 'Later',
+  'upd.downloading': 'Downloading…', 'upd.installing': 'Installing…',
+  'upd.restartNote': 'OpsLog will restart on the new version.',
+  'upd.retry': 'Retry', 'upd.browser': 'Open page',
   'rate.title': 'QSO rate (QSOs/hour) — projected from the last 10 / 60 minutes',
   'lotw.userTip': 'LoTW user — last upload {date} ({days} days ago)',
   'menu.file': 'File', 'menu.edit': 'Edit', 'menu.view': 'View', 'menu.tools': 'Tools',
@@ -324,6 +332,9 @@ const en: Dict = {
 
 const fr: Dict = {
   'prop.title': 'Propagation', 'prop.geomag': 'Géomag', 'prop.refresh': 'Actualiser la météo spatiale',
+  'live.onAir': 'On air', 'live.offline': 'Hors ligne',
+  'live.onAirTip': "On air — un QSO a été loggé dans les 5 dernières minutes (publié dans le statut live)",
+  'live.offlineTip': 'Hors ligne — aucun QSO loggé depuis 5 minutes',
   'rate.title': 'Rythme QSO (QSO/heure) — projeté sur les 10 / 60 dernières minutes',
   'lotw.userTip': 'Utilisateur LoTW — dernier upload {date} (il y a {days} j)',
   'menu.file': 'Fichier', 'menu.edit': 'Édition', 'menu.view': 'Affichage', 'menu.tools': 'Outils',