feat(nutrition,health_sync): complete Phase 3 nutrition tracking and HealthGateway sync
- Domain: FoodLogEntry/MealType, HydrationLogEntry, BiometricEntry/BiometricSource entities plus INutritionRepository and IHealthSyncRepository contracts (pure Dart).
- Data: AppDatabase schema v2 (FoodLogs/HydrationLogs/BiometricLogs tables, v1 migration, range-filtered CRUD) with drift-backed NutritionRepository and HealthSyncRepository; startOfDay/endOfDay date utils.
- Platform: HealthGateway conditional-import factory - mobile impl wires package:health (WEIGHT kg->lb, ACTIVE_ENERGY_BURNED J->kcal, permissions, write-back) with guarded fallbacks; web/desktop impl never touches platform channels (manual entry + drift cache).
- Presentation: NutritionController and BiometricController AsyncNotifiers (100g protein / 96oz water targets, meal grouping, 7/30-day weight deltas, idempotent 90-day native sync with per-day active-energy aggregation); LogFoodDialog and LogWeightDialog.
- UI: NutritionScreen progress meters, +8/+16/+24oz quick-add, meal-grouped food diary, weight tracker card with Log Weight / Sync (native sync on Android/iOS, manual dialog on Windows/Web) and status snackbars.
- Tests: 23 new tests (in-memory drift repos, controller fakes, fake health gateway covering fallback, permission denial, and duplicate-free re-sync); 60/60 passing, flutter analyze clean, flutter build web succeeds. BUILD_STATE.md updated to Phase 4.
Mike Kell
094cf08f25