feat(bandmap): draw the band plan of the operator's IARU region

The band maps carried one hard-coded table — Region 1's — so a US operator's
40 m stopped at 7200 with stations spotted at 7250 hanging past the top of the
map, and the SSB wash started 25 kHz early. The region is a station-level fact
stated once (Settings → General, portable pref); lib/bandplan owns the three
tables and publishes changes to the open maps the way the distance unit reaches
the grids.

The tables stay deliberately coarse: a band map's wash is context, not a
regulatory chart, so only the differences an operator notices are split out —
Region 2's 80 m to 4000 and 40 m to 7300 (phone from 7125), Region 3's 80 m to
3900, the wider VHF/UHF allocations. National fine print does not belong in a
background tint.

frontend/src/lib/i18n.tsx

@@ -130,6 +130,8 @@ const en: Dict = {
   'icmp.scopeNoStream': 'This radio does not send its scope over CI-V — its own screen still works.',
   'wk.catWarnTci': 'The CW keyer is set to the radio, but the CAT backend is "{backend}". Pick TCI in Settings → CAT, or another keying engine.',
   'wk.tciHint': "Keying goes through the radio's own macro keyer, over the link already open — no WinKeyer and no second serial port. The radio can stop a message but cannot un-type one, so there is no type-ahead correction here.",
+  'gen.iaruRegion': 'IARU region', 'gen.iaruHint': '(band plan drawn on the band maps)',
+  'gen.iaruR1': 'Region 1 — Europe, Africa, Middle East', 'gen.iaruR2': 'Region 2 — Americas', 'gen.iaruR3': 'Region 3 — Asia-Pacific',
   'gen.miles': 'Distances in miles', 'gen.milesHint': '(instead of kilometres)',
   'qslm.thStation': 'Station',
   'qslm.qrzTitle': 'Open this callsign on QRZ.com',
@@ -631,6 +633,8 @@ const fr: Dict = {
   'icmp.scopeNoStream': "Cette radio n'envoie pas son scope en CI-V — son propre écran fonctionne toujours.",
   'wk.catWarnTci': "Le manipulateur CW est réglé sur la radio, mais le backend CAT est « {backend} ». Choisissez TCI dans Réglages → CAT, ou un autre moteur de manipulation.",
   'wk.tciHint': "La manipulation passe par le keyer à macros de la radio, sur la liaison déjà ouverte — ni WinKeyer ni second port série. La radio sait interrompre un message mais pas en effacer la fin, donc pas de correction en frappe anticipée ici.",
+  'gen.iaruRegion': 'Région IARU', 'gen.iaruHint': '(plan de bande dessiné sur les cartes de bande)',
+  'gen.iaruR1': 'Région 1 — Europe, Afrique, Moyen-Orient', 'gen.iaruR2': 'Région 2 — Amériques', 'gen.iaruR3': 'Région 3 — Asie-Pacifique',
   'gen.miles': 'Distances en miles', 'gen.milesHint': '(au lieu des kilomètres)',
   'qslm.thStation': 'Station',
   'qslm.qrzTitle': 'Ouvrir cet indicatif sur QRZ.com',