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/onboarding.tsx

@@ -999,7 +999,7 @@ export default function OnboardingScreen() {
       if (plan !== 'free') {
         setSubscription(plan)
       }
-      router.replace('/(tabs)')
+      router.replace('/')
     },
     [name, level, goal, frequency, barriers, step]
   )