Cloud connector framework: ICloudHealthConnector contract, supportsCloudSync / isCloudSyncReady on IHealthGateway, and a HealthProviderType.googleHealth slot; a conditional-import shim (io implementation / web stub) keeps platform channels out of web builds.
Google Health connector (successor to the retired Fitbit Web API, shutdown 2026-10-30): OAuth2 authorization-code + PKCE through the system browser with a loopback redirect; read-only activity-and-fitness + health-metrics scopes; tokens in flutter_secure_storage with transparent refresh; paginated weight and active-energy-burned dataPoints reads with kg-to-lb normalization from the per-point unit field; pure unit-tested parsers.
Gateway wiring: both drivers store injected connectors (desktop runs MobileHealthGateway through the io conditional import; the fallback driver is web-only); cloud status/authorize/disconnect route first and reads merge native + cloud non-fatally; syncFromHealth accepts cloud-only sources and imports persist as BiometricSource.cloudSync.
UI: Google Health row in Settings with Connect/Disconnect and auto-import on connect; explanatory desktop copy on the Apple Health and Health Connect rows; the Nutrition weight card syncs through a connected cloud partner and surfaces the outcome as a snackbar, degrading to the manual dialog when no source is connected.
Field fixes recorded in BUILD_STATE: io-driver connector wiring, duplicate-implementation merge correction, weight-card sync gate. Tests: google_health_parser_test suite; settings_screen_test updated for the fourth integration row. The legacy Fitbit connector was fully removed before shipping.
Implements architecture section 4.7: IHealthGateway now exposes the Phase 3B contract (HealthProviderType, HealthConnectionStatus, HealthDataPayload, checkStatus/requestAuthorization/fetchLatestBiometrics/disconnect) with defaults derived from the existing primitives. Drivers and test fakes switch from implements to extends so Dart inherits the default bodies.
- Mobile driver: BLOOD_GLUCOSE added to iOS/Android read sets (mmol/L to mg/dL normalization); checkStatus probes hasPermissions plus Health Connect SDK readiness; samsungHealth aliases the Health Connect binding on Android (federated Samsung/Pixel feeds); disconnect clears the cached SDK probe.
- Fallback driver: safe dummy states on Windows/Web/macOS (manualFallback connected, enterpriseFhir notConfigured, native unsupportedPlatform); fetchLatestBiometrics serves the encrypted drift cache; zero platform-channel calls.
- Settings: IntegrationsController rewritten from toggles to status orchestration (refreshStatuses, connect/disconnect round-trips, denial to permissionDenied plus snackbar); SettingsScreen gains a Health Integrations card with Apple Health, Health Connect (Samsung & Pixel), and SMART on FHIR rows showing live status badges and Connect/Disconnect buttons with desktop-safe disabled states.
- Manifests: Android adds READ_BLOOD_GLUCOSE, healthdata package query, ACTION_SHOW_PERMISSIONS_RATIONALE intent, and ViewPermissionUsageActivity alias; iOS adds NSHealthShareUsageDescription and NSHealthUpdateUsageDescription.
- Tests: +13 (fallback dummy-state matrix, integrations controller transitions, Settings desktop disabled-states and mobile connect/disconnect round trip); existing fake switched to extends; navigation test updated for the renamed card title.
Verified: build_runner 191 outputs; flutter analyze clean; flutter test 148/148; flutter build windows debug succeeded.
Mike Kell