/native

Boundaries — Full Elaboration

Full rationale, citations, and threshold detail behind the condensed ## Boundaries bullets in SKILL.md.

Always (elaboration)

• Detect target platform(s) before writing any code. iOS + Android = two separate codebases, each idiomatic.
• Follow Apple HIG (Liquid Glass on iOS 26, classic HIG on iOS 17/18) and Material 3 Expressive (Android).
• Implement an offline fallback (minimum T0) for any network-dependent feature.
• Use platform-native navigation: NavigationStack / NavigationSplitView + Coordinator on iOS; Navigation Compose 2.8+ type-safe on Android.
• Handle every permission with a soft pre-prompt UX and graceful denial path.
• Write strict-typed code: Swift 6 strict concurrency; Kotlin explicit nullability; Compose Strong Skipping with @Immutable where instance-equality recomposition is a risk.
• Draft Privacy Manifest (iOS) and Data Safety form (Android) alongside the feature. Hand off to Cloak.
• Plan store compliance from MVP: Privacy Manifest, Data Safety, Sign in with Apple alongside any third-party login, AI disclosure UI, Photo Picker (Android), Liquid Glass icon variants (iOS 26).
• Default sign-in to Passkey (iOS 26 ASAuthorizationAccountCreationProvider / iOS 17-18 ASAuthorizationController / Android Credential Manager); preferImmediatelyAvailableCredentials for silent fallback; OAuth/OIDC (ASWebAuthenticationSession + PKCE on iOS, AppAuth + Custom Tabs on Android) only when an existing IdP requires it.
• In-flow passkey nudge after OTP/password success (KAYAK/eBay pattern → 75% creation vs ~3% non-nudged).
• SwiftData: define Schema + VersionedSchema + SchemaMigrationPlan from first release — retrofitting breaks production relationship integrity.
• Liquid Glass scope: apply .glassEffect() to navigation chrome only (NavigationBar / TabBar / Toolbar / Sheet / Popover). Never content. Standard SwiftUI components auto-adopt on Xcode 26 recompile.
• @Observable ownership: declare with @State only in the owning view; pass to children via let / @Bindable / @Environment. Child-side @State re-inits the model.
• Reference reference/ for detail patterns; keep SKILL.md procedural and routable.

Ask First (elaboration)

• Target platform ambiguous (iOS only / Android only / both).
• Offline tier unclear (T0-T3 selection).
• IAP design involves server-side receipt validation architecture.
• Feature requires custom native module (e.g., 3rd-party SDK without Privacy Manifest).
• iOS baseline: default 17; 16 acceptable; 26+ required for Liquid Glass / Foundation Models; 15 needs justification.
• Android baseline: default API 28; API 31+ required for Material You / SplashScreen / Photo Picker.
• targetSdk 36 timing — mandatory by 2026-08-31; plan migration before deadline.

Never (elaboration)

• Implement React Native / Flutter / Kotlin Multiplatform / Compose Multiplatform. Out of scope — route to Forge.
• Ship without testing on both platforms when both are in scope.
• Hard-code API keys / secrets client-side (MASWE-0005; Zimperium 2025: ~50% of apps, trivially extracted by MobSF / APKLeaks). Use Keychain (iOS) / Tink-encrypted DataStore (Android); proxy via BFF.
• Store tokens in UserDefaults / SharedPreferences — use Keychain (.biometryCurrentSet + kSecAttrAccessibleWhenUnlockedThisDeviceOnly) / Tink-encrypted DataStore.
• Apply .glassEffect() to content layers (lists, cards, body) — restrict to navigation chrome.
• Force TabBar / NavigationBar opaque on iOS 26 to hide Liquid Glass — adapt content instead.
• Declare @unchecked Sendable to silence strict-concurrency — fix isolation via actor / @MainActor / Sendable.
• Treat @Observable as drop-in ObservableObject — child-side @State re-inits and duplicates observation.
• Use EncryptedSharedPreferences on Android — deprecated in security-crypto:1.1.0-alpha07. Migrate to Tink-encrypted DataStore / datastore-encrypted 1.3.0-alpha07+.
• Keep onBackPressed() / KEYCODE_BACK on targetSdk 36 — not invoked. Migrate to OnBackPressedDispatcher / PredictiveBackHandler + android:enableOnBackInvokedCallback="true".
• Lock screenOrientation="portrait" / resizeableActivity="false" on Android 16 — ignored for sw600dp+. PROPERTY_COMPAT_ALLOW_RESTRICTED_RESIZABILITY disappears at API 37.
• Pin third-party domains via cert pinning — restrict to first-party endpoints, public-key pinning with ≥ 2 backups, reserve for finance/health (OWASP 2025 toned down general recommendation).
• Hardcode messageformat or English plural rules — Russian/Arabic have 6 forms. Use ICU {count, plural, ...} via String Catalogs / plurals.xml; hand off to Polyglot.
• Bypass App Review or Play Policy for faster release.
• Apply web-only patterns (localStorage, window.location, cookie-bearing fetch) on mobile.
• Skip offline handling for network-dependent features.
• Hide platform divergence — if iOS and Android need different solutions, document and ship separately.
• Promise OTA updates of native code. Not supported by App Store / Play — use Phased Release / Staged Rollout.
• Ignore platform lifecycle events (backgrounding, memory warnings, Doze, app standby).
• Ship UI without Privacy Manifest / Data Safety completion — both stores reject submissions.