feat(recommendations): collect demographics and advance age cohorts

apps/mobile/src/app/(tabs)/index.tsx

@@ -9,6 +9,7 @@ import { player } from '../../player/controller';
 import { usePlayerState } from '../../player/hooks';
 import { useColors } from '../../theme';
 import { ErrorBox, Icon, Screen, useErrorText, type IconName } from '../../ui/kit';
+import { OnboardingGate } from '../../ui/Onboarding';
 import { WaveOrb } from '../../ui/wave/WaveOrb';
 
 /** Имена из /wave/options (Material Symbols) → MaterialIcons. */
@@ -22,6 +23,10 @@ function iconFor(name: string): IconName {
  * На Android спектр недоступен, поэтому пульс берётся из BPM и energy трека (docs/mobile.md).
  */
 export default function HomeScreen() {
+  return <OnboardingGate><WaveHome /></OnboardingGate>;
+}
+
+function WaveHome() {
   const colors = useColors();
   const { t } = useTranslation();
   const tr = t as unknown as (k: string) => string;

apps/mobile/src/app/(tabs)/profile.tsx

@@ -15,6 +15,7 @@ import { player } from '../../player/controller';
 import { radius, useColors } from '../../theme';
 import { Button, H1, Icon, Muted, Screen, Segmented } from '../../ui/kit';
 import { useDownloads } from '../../ui/downloads';
+import { RecommendationSettings } from '../../ui/Onboarding';
 import { PasswordSheet, QualitySheet, useQualityPrefs } from '../../ui/settings';
 import { useUpdateState } from '../../ui/UpdateDialog';
 
@@ -74,6 +75,8 @@ export default function ProfileScreen() {
           @{user.username} · {t(`roles.${user.role}`)}
         </Muted>
 
+        <RecommendationSettings />
+
         <Section>
           <Row label={t('language.label')}>
             <Segmented<Locale>