style(settings): three more explanations off the General panel

The SCP paragraph, the digital-grouping parenthetical and the IARU region hint
all move into tooltips on their own controls.

frontend/src/components/SettingsModal.tsx

@@ -6778,7 +6778,7 @@ function SettingsModalImpl({ onClose, onSaved, initialSection, onMainPaneChanged
               useLocalLogbook(); // SQLite → default logbook file (clears any per-profile path)
             }}
           >
-            <SelectTrigger className="h-8 w-72"><SelectValue /></SelectTrigger>
+            <SelectTrigger className="h-8 w-72" title={t('gen.iaruHint')}><SelectValue /></SelectTrigger>
             <SelectContent>
               <SelectItem value="sqlite">{t('db.optSqlite')}</SelectItem>
               <SelectItem value="mysql">{t('db.optMysql')}</SelectItem>
@@ -7200,7 +7200,6 @@ function SettingsModalImpl({ onClose, onSaved, initialSection, onMainPaneChanged
                 <SelectItem value="3">{t('gen.iaruR3')}</SelectItem>
               </SelectContent>
             </Select>
-            <span className="text-xs text-muted-foreground">{t('gen.iaruHint')}</span>
           </div>
 
           <ThemeSelector />
@@ -7224,11 +7223,10 @@ function SettingsModalImpl({ onClose, onSaved, initialSection, onMainPaneChanged
           {/* Super Check Partial / N+1 — downloads the community MASTER.SCP list and
               shows a two-column callsign helper (partial matches + one-edit calls). */}
           <div className="border-t border-border/60 pt-3 space-y-2">
-            <label className="flex items-center gap-2 text-sm cursor-pointer">
+            <label className="flex items-center gap-2 text-sm cursor-pointer" title={t('scp.settingsHint')}>
               <Checkbox checked={scp.enabled} disabled={scpBusy} onCheckedChange={(c) => toggleScp(!!c)} />
               {t('scp.enable')}
             </label>
-            <p className="text-[11px] text-muted-foreground">{t('scp.settingsHint')}</p>
             {scp.enabled && (
               <div className="flex items-center gap-3">
                 <Button variant="outline" size="sm" onClick={downloadScp} disabled={scpBusy}>
@@ -7256,7 +7254,7 @@ function SettingsModalImpl({ onClose, onSaved, initialSection, onMainPaneChanged
           </label>
           <label className="flex items-center gap-2 text-sm cursor-pointer">
             <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>
+            <span title={t('gen.groupDigitalHint')}>{t('gen.groupDigital')}</span>
           </label>
           <label className="flex items-center gap-2 text-sm cursor-pointer">
             {/* Distances are computed in km everywhere and converted at display