Identity: rename the application identity to com.companionglp.glpcompanion on every platform (Android applicationId/namespace + MainActivity package, iOS/macOS bundle IDs incl. RunnerTests, Windows CompanyName/copyright, web manifest id, Supabase OAuth redirect scheme).
Deep links: register the custom scheme com.companionglp.glpcompanion:// in iOS/macOS Info.plist (CFBundleURLTypes), the Android VIEW/BROWSABLE intent-filter, and Windows per-user HKCU protocol registration. Server-side steps (Supabase uri_allow-list, Entra optional email claim) are recorded in BUILD_STATE.md.
Windows runner: single-instance mutex (Local\GLPCompanionSingleInstance) so login callbacks are delivered deterministically; SendAppLinkToInstance forwarding with foreground/taskbar-flash fallback so protocol activation can never look like a hang; protocol diagnostics appended to TEMP glpcompanion-protocol.log.
macOS: add the missing com.apple.security.network.client entitlement so the sandboxed runner can reach Supabase at all.
Auth UX: surface deferred OAuth/magic-link handshake failures as snackbars on the login screen; make isAuthenticatedProvider reactive (watches authStateProvider) with a microtask-deferred router refresh so live sign-in and sign-out redirect correctly; add a debug package:logging listener so supabase_flutter diagnostics are visible under flutter run.
Field-verified on Windows: Google, Microsoft (Entra ID), and email magic-link sign-in round trips plus sign-out redirect to /login.
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