feat: Apple Watch app + Paywall + Privacy Policy + rebranding

## Major Features
- Apple Watch companion app (6 phases complete)
  - WatchConnectivity iPhone ↔ Watch
  - HealthKit integration (HR, calories)
  - SwiftUI premium UI
  - 9 complication types
  - Always-On Display support

- Paywall screen with RevenueCat integration
- Privacy Policy screen
- App rebranding: tabatago → TabataFit
- Bundle ID: com.millianlmx.tabatafit

## Changes
- New: ios/TabataFit Watch App/ (complete Watch app)
- New: app/paywall.tsx (subscription UI)
- New: app/privacy.tsx (privacy policy)
- New: src/features/watch/ (Watch sync hooks)
- New: admin-web/ (admin dashboard)
- Updated: app.json, package.json (branding)
- Updated: profile.tsx (paywall + privacy links)
- Updated: i18n translations (EN/FR/DE/ES)
- New: app icon 1024x1024

## Watch App Files
- TabataFitWatchApp.swift (entry point)
- ContentView.swift (premium UI)
- HealthKitManager.swift (HR + calories)
- WatchSessionManager.swift (communication)
- Complications/ (WidgetKit)
- UserDefaults+Shared.swift (data sharing)

app/onboarding.tsx

@@ -29,7 +29,7 @@ import type { ThemeColors } from '@/src/shared/theme/types'
 import { SPACING, LAYOUT } from '@/src/shared/constants/spacing'
 import { RADIUS } from '@/src/shared/constants/borderRadius'
 import { DURATION, EASE, SPRING } from '@/src/shared/constants/animations'
-import { track } from '@/src/shared/services/analytics'
+import { track, identifyUser, setUserProperties, trackScreen } from '@/src/shared/services/analytics'
 
 import type { FitnessLevel, FitnessGoal, WeeklyFrequency } from '@/src/shared/types'
 
@@ -938,25 +938,43 @@ export default function OnboardingScreen() {
 
   // Track onboarding_started + first step viewed on mount
   useEffect(() => {
+    trackScreen('onboarding')
     track('onboarding_started')
     track('onboarding_step_viewed', { step: 1, step_name: STEP_NAMES[1] })
   }, [])
 
   const finishOnboarding = useCallback(
     (plan: 'free' | 'premium-monthly' | 'premium-yearly') => {
+      const totalTime = Date.now() - onboardingStartTime.current
+
       track('onboarding_completed', {
         plan,
-        total_time_ms: Date.now() - onboardingStartTime.current,
+        total_time_ms: totalTime,
         steps_completed: step,
       })
 
-      completeOnboarding({
+      const userData = {
         name: name.trim() || 'Athlete',
         fitnessLevel: level,
         goal,
         weeklyFrequency: frequency,
         barriers,
+      }
+
+      completeOnboarding(userData)
+
+      // Identify user in PostHog for session replay linking
+      const userId = `user_${Date.now()}` // In production, use actual user ID from backend
+      identifyUser(userId, {
+        name: userData.name,
+        fitness_level: level,
+        fitness_goal: goal,
+        weekly_frequency: frequency,
+        subscription_plan: plan,
+        onboarding_completed_at: new Date().toISOString(),
+        barriers: barriers.join(','),
       })
+
       if (plan !== 'free') {
         setSubscription(plan)
       }