feat: explore tab, React Query data layer, programs, sync, analytics, testing infrastructure

- Replace browse tab with Supabase-connected explore tab with filters
- Add React Query for data fetching with loading states
- Add 3 structured programs with weekly progression
- Add Supabase anonymous auth sync service
- Add PostHog analytics with screen tracking and events
- Add comprehensive test strategy (Vitest + Maestro E2E)
- Add RevenueCat subscription system with DEV simulation
- Add i18n translations for new screens (EN/FR/DE/ES)
- Add data deletion modal, sync consent modal
- Add assessment screen and program routes
- Add GitHub Actions CI workflow
- Update activity store with sync integration

.maestro/flows/onboarding.yaml

@@ -0,0 +1,46 @@
+# Onboarding Flow Test
+# Tests the complete 6-step onboarding process
+
+appId: com.millianlmx.tabatafit
+name: Onboarding Flow
+
+---
+- launchApp
+# Step 1: Problem Screen
+- assertVisible: "onboarding-problem-cta"
+- tapOn: "onboarding-problem-cta"
+
+# Step 2: Empathy Screen - Select barriers
+- assertVisible: "barrier-no-time"
+- tapOn: "barrier-no-time"
+- tapOn: "barrier-low-motivation"
+- assertVisible: "onboarding-empathy-continue"
+- tapOn: "onboarding-empathy-continue"
+
+# Step 3: Solution Screen
+- assertVisible: "onboarding-solution-cta"
+- tapOn: "onboarding-solution-cta"
+
+# Step 4: Wow Screen (features reveal)
+- assertVisible: "onboarding-wow-cta"
+- tapOn: "onboarding-wow-cta"
+
+# Step 5: Personalization
+- assertVisible: "name-input"
+- tapOn: "name-input"
+- inputText: "Test User"
+
+- tapOn: "level-intermediate"
+- tapOn: "goal-strength"
+- tapOn: "frequency-3x"
+
+- assertVisible: "onboarding-personalization-continue"
+- tapOn: "onboarding-personalization-continue"
+
+# Step 6: Paywall - Skip subscription
+- assertVisible: "subscribe-button"
+- assertVisible: "skip-paywall"
+- tapOn: "skip-paywall"
+
+# Verify we're on the home screen
+- assertVisible: "program-card-upper-body"