fix(bandopen): stop subscribing to a band nobody watches, and drop the toast

A saved band selection outlives the code that made it. 12 m was removed from the
watched set, but every operator who had already enabled the watch kept
subscribing to it — paying for a firehose whose messages the detector then threw
away. The stored list is filtered against the offered one now.

The badge appeared on the next poll rather than on the event, up to twenty
seconds after the announcement, so the two read as unrelated things that happened
to mention the same band. It appears immediately.

And the toast is gone. It said the same thing as the badge and vanished after
five seconds — an operator who was tuning when it passed had no way back to it,
which is precisely what the badge was built to fix. Keeping both announced an
opening twice and still lost it once.

frontend/src/lib/i18n.tsx

@@ -347,7 +347,7 @@ const en: Dict = {
   'bmp.statusWorked': 'Worked (this band + mode already in log)', 'bmp.statusUnresolved': 'Entity not resolved', 'bmp.bandMap': 'Band map', 'bmp.notConfigured': 'Not configured for {band}.',
   'bmp.map': 'Map', 'bmp.zoomOut': 'Zoom out', 'bmp.zoomIn': 'Zoom in', 'bmp.scrollToRig': 'Scroll to current rig frequency', 'bmp.moveLeft': 'Move band map to the left', 'bmp.moveRight': 'Move band map to the right', 'bmp.hide': 'Hide band map',
   'bmp.bandsLabel': 'Bands:', 'bmp.fit': 'FIT', 'bmp.hideFt': 'Hide FTx', 'bmp.hideFtTitle': 'Hide all digital (FT8/FT4/JS8/…) spots on every band map', 'bmp.fitBand': 'Fit to band', 'bmp.widthTip': 'Drag to resize — double-click to reset', 'bmp.fitTitle': 'Size each band map to show the whole band edge-to-edge',
-  'bmp.legendNewDxcc': 'New DXCC', 'bmp.legendNewBand': 'New band', 'bmp.legendNewSlot': 'New slot (mode)', 'bmp.openToast': '{band} is open — {n} stations around {km} km', 'bmp.openUnusual': 'unusual for the season', 'bmp.legendWorked': 'Worked', 'bmp.legendNewPota': 'New POTA', 'bmp.legendNewCounty': 'New county', 'bmp.legendWorkedCall': 'Callsign already worked', 'bmp.legendCW': 'CW', 'bmp.legendData': 'Data', 'bmp.legendPhone': 'Phone', 'bmp.footerHint': 'scroll · ctrl+wheel = zoom · ◎ = jump to rig', 'bmp.spotsHidden': '{n} FT8/FT4 spots hidden — top {max} kept (CW/SSB all shown)',
+  'bmp.legendNewDxcc': 'New DXCC', 'bmp.legendNewBand': 'New band', 'bmp.legendNewSlot': 'New slot (mode)', 'bmp.openUnusual': 'unusual for the season', 'bmp.legendWorked': 'Worked', 'bmp.legendNewPota': 'New POTA', 'bmp.legendNewCounty': 'New county', 'bmp.legendWorkedCall': 'Callsign already worked', 'bmp.legendCW': 'CW', 'bmp.legendData': 'Data', 'bmp.legendPhone': 'Phone', 'bmp.footerHint': 'scroll · ctrl+wheel = zoom · ◎ = jump to rig', 'bmp.spotsHidden': '{n} FT8/FT4 spots hidden — top {max} kept (CW/SSB all shown)',
   'frm.welcome': 'Welcome to OpsLog', 'frm.intro': 'Set up your station to start logging. These fields stamp every QSO and can be changed later in Preferences → Station Information (and per profile).',
   'frm.callsign': 'Callsign', 'frm.locator': 'Locator', 'frm.operator': 'Operator', 'frm.operatorPh': 'same as callsign', 'frm.owner': 'Owner', 'frm.ownerPh': 'station owner callsign', 'frm.name': 'Name', 'frm.namePh': 'your first name',
   'frm.awardRefs': 'Award reference lists', 'frm.awardRefsHint': 'IOTA · POTA · WWFF · SOTA — names & totals for those awards (optional, can take a minute).', 'frm.downloading': 'Downloading…', 'frm.reDownload': 'Re-download', 'frm.download': 'Download', 'frm.required': 'Callsign and locator are required.', 'frm.saving': 'Saving…', 'frm.startLogging': 'Start logging',
@@ -759,7 +759,7 @@ const fr: Dict = {
   'bmp.statusWorked': 'Contacté (cette bande + mode déjà au log)', 'bmp.statusUnresolved': 'Entité non résolue', 'bmp.bandMap': 'Carte de bande', 'bmp.notConfigured': 'Non configurée pour {band}.',
   'bmp.map': 'Carte', 'bmp.zoomOut': 'Dézoomer', 'bmp.zoomIn': 'Zoomer', 'bmp.scrollToRig': 'Aller à la fréquence actuelle du poste', 'bmp.moveLeft': 'Déplacer la carte de bande à gauche', 'bmp.moveRight': 'Déplacer la carte de bande à droite', 'bmp.hide': 'Masquer la carte de bande',
   'bmp.bandsLabel': 'Bandes :', 'bmp.fit': 'FIT', 'bmp.hideFt': 'Masquer FTx', 'bmp.hideFtTitle': 'Masquer tous les spots numériques (FT8/FT4/JS8/…) sur toutes les cartes', 'bmp.fitBand': 'Ajuster à la bande', 'bmp.widthTip': 'Glisser pour redimensionner — double-clic pour réinitialiser', 'bmp.fitTitle': 'Dimensionner chaque carte pour afficher toute la bande',
-  'bmp.legendNewDxcc': 'Nouveau DXCC', 'bmp.legendNewBand': 'Nouvelle bande', 'bmp.legendNewSlot': 'Nouveau mode', 'bmp.openToast': 'Ouverture {band} — {n} stations vers {km} km', 'bmp.openUnusual': 'inhabituel pour la saison', 'bmp.legendWorked': 'Contacté', 'bmp.legendNewPota': 'Nouveau POTA', 'bmp.legendNewCounty': 'Nouveau comté', 'bmp.legendWorkedCall': 'Indicatif déjà contacté', 'bmp.legendCW': 'CW', 'bmp.legendData': 'Numérique', 'bmp.legendPhone': 'Phonie', 'bmp.footerHint': 'défiler · ctrl+molette = zoom · ◎ = aller au poste', 'bmp.spotsHidden': '{n} spots FT8/FT4 masqués — {max} meilleurs conservés (CW/SSB tous affichés)',
+  'bmp.legendNewDxcc': 'Nouveau DXCC', 'bmp.legendNewBand': 'Nouvelle bande', 'bmp.legendNewSlot': 'Nouveau mode', 'bmp.openUnusual': 'inhabituel pour la saison', 'bmp.legendWorked': 'Contacté', 'bmp.legendNewPota': 'Nouveau POTA', 'bmp.legendNewCounty': 'Nouveau comté', 'bmp.legendWorkedCall': 'Indicatif déjà contacté', 'bmp.legendCW': 'CW', 'bmp.legendData': 'Numérique', 'bmp.legendPhone': 'Phonie', 'bmp.footerHint': 'défiler · ctrl+molette = zoom · ◎ = aller au poste', 'bmp.spotsHidden': '{n} spots FT8/FT4 masqués — {max} meilleurs conservés (CW/SSB tous affichés)',
   'frm.welcome': 'Bienvenue dans OpsLog', 'frm.intro': 'Configure ta station pour commencer à logger. Ces champs sont inscrits sur chaque QSO et peuvent être modifiés plus tard dans Préférences → Informations station (et par profil).',
   'frm.callsign': 'Indicatif', 'frm.locator': 'Locator', 'frm.operator': 'Opérateur', 'frm.operatorPh': "identique à l'indicatif", 'frm.owner': 'Propriétaire', 'frm.ownerPh': 'indicatif du propriétaire de la station', 'frm.name': 'Nom', 'frm.namePh': 'ton prénom',
   'frm.awardRefs': 'Listes de références des diplômes', 'frm.awardRefsHint': 'IOTA · POTA · WWFF · SOTA — noms et totaux pour ces diplômes (optionnel, peut prendre une minute).', 'frm.downloading': 'Téléchargement…', 'frm.reDownload': 'Retélécharger', 'frm.download': 'Télécharger', 'frm.required': "L'indicatif et le locator sont obligatoires.", 'frm.saving': 'Enregistrement…', 'frm.startLogging': 'Commencer à logger',