refactor screens, navigation & player for new architecture

Simplify Home, Activity, Profile, Complete, Player, and Program screens
to work with the new Supabase-driven data layer. Update root and tab
layouts. Add Settings, Terms, and Zone routes. Add OfflineBanner
component and progressStore. Update all player sub-components to use
the refreshed design system tokens.

app/privacy.tsx

@@ -13,7 +13,7 @@ import { useTranslation } from 'react-i18next'
 import { useHaptics } from '@/src/shared/hooks'
 import { darkColors, BRAND } from '@/src/shared/theme'
 import { SPACING } from '@/src/shared/constants/spacing'
-import { TYPOGRAPHY, FONT_FAMILY } from '@/src/shared/constants/typography'
+import { TYPOGRAPHY } from '@/src/shared/constants/typography'
 
 export default function PrivacyPolicyScreen() {
   const { t } = useTranslation('screens')
@@ -169,7 +169,7 @@ const styles = StyleSheet.create({
   },
   sectionTitle: {
     ...TYPOGRAPHY.TITLE_3,
-    fontFamily: FONT_FAMILY.SANS_BOLD,
+    fontWeight: '700',
     color: darkColors.text.primary,
     marginBottom: SPACING[3],
   },