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/components/SettingsModal.tsx

@@ -81,6 +81,7 @@ import {
 import { cn } from '@/lib/utils';
 import { writeUiPref } from '@/lib/uiPref';
 import { setUseMiles } from '@/lib/units';
+import { iaruRegion, setIaruRegion, type IaruRegion } from '@/lib/bandplan';
 import { getDateFormat, setDateFormat, type DateFormat } from '@/lib/dateFormat';
 import { useI18n, FlagGB, FlagFR, type Lang } from '@/lib/i18n';
 import { useTheme, CONCRETE_THEMES, type ThemeChoice } from '@/lib/theme';
@@ -1749,6 +1750,7 @@ function SettingsModalImpl({ onClose, onSaved, initialSection, onMainPaneChanged
   const [lookupOnBlur, setLookupOnBlur] = useState(() => localStorage.getItem('opslog.lookupOnBlur') === '1');
   const [groupDigital, setGroupDigital] = useState(() => localStorage.getItem('opslog.groupDigitalSlots') === '1');
   const [milesUnit, setMilesUnit] = useState(() => localStorage.getItem('opslog.distanceMiles') === '1');
+  const [region, setRegion] = useState<IaruRegion>(() => iaruRegion());
   const [clusterWorkedSameSlot, setClusterWorkedSameSlot] = useState(() => localStorage.getItem('opslog.clusterWorkedSameSlot') === '1');
   // Declared HERE and not in ClusterPanel: that renderer is called as a plain
   // function by the PANELS map, so it must stay hooks-free.
@@ -7239,6 +7241,24 @@ function SettingsModalImpl({ onClose, onSaved, initialSection, onMainPaneChanged
             <Checkbox checked={groupDigital} onCheckedChange={(c) => { const v = !!c; setGroupDigital(v); writeUiPref('opslog.groupDigitalSlots', v ? '1' : '0'); }} />
             {t('gen.groupDigital')} <span className="text-xs text-muted-foreground">{t('gen.groupDigitalHint')}</span>
           </label>
+          <div className="flex items-center gap-2 text-sm">
+            {/* The IARU region drives the band edges and mode segments the band
+                maps draw — Region 2's 40 m runs to 7300, Region 1's stops at
+                7200 — and nothing else: spots and logging are region-blind. */}
+            <span>{t('gen.iaruRegion')}</span>
+            <Select value={String(region)} onValueChange={(v) => {
+              const r = (v === '2' ? 2 : v === '3' ? 3 : 1) as IaruRegion;
+              setRegion(r); setIaruRegion(r);
+            }}>
+              <SelectTrigger className="h-8 w-64"><SelectValue /></SelectTrigger>
+              <SelectContent>
+                <SelectItem value="1">{t('gen.iaruR1')}</SelectItem>
+                <SelectItem value="2">{t('gen.iaruR2')}</SelectItem>
+                <SelectItem value="3">{t('gen.iaruR3')}</SelectItem>
+              </SelectContent>
+            </Select>
+            <span className="text-xs text-muted-foreground">{t('gen.iaruHint')}</span>
+          </div>
           <label className="flex items-center gap-2 text-sm cursor-pointer">
             {/* Distances are computed in km everywhere and converted at display
                 time — see lib/units. Changing this repaints the columns that