feat: clone Opal's rules feature with hard block enforcement

Rebuild the app around recurring screen-time blocking rules modeled on
Opal's My Apps tab:

- Onboarding with FamilyControls Screen Time authorization
- Apps home with Blocked Apps tiles and live rule cards
- New Rule sheet: Schedule/Time Limit/Open Limit types + preset gallery
- Rule editors: time windows (incl. overnight), day picker, app selection
  via FamilyActivityPicker (Block/Allow Only), rename, Hold to Commit
- Hard Mode: active hard rules cannot be edited, disabled, deleted, or
  unblocked until their window ends; soft rules pause until next window
- Shield enforcement through per-rule ManagedSettingsStore + RuleEnforcer
- 73 unit tests (Swift Testing) + 16 UI tests (XCUITest) with launch-arg
  harness for in-memory storage, mocked authorization, seeded scenarios
- docs/RULES_FEATURE_SPEC.md: spec derived from the reference recording

Known gap: background window transitions and time/open-limit thresholds
need a DeviceActivityMonitor extension; shields currently sync while the
app is running.

Co-Authored-By: Claude <noreply@anthropic.com>

Severed/SeveredApp.swift

@@ -5,28 +5,57 @@
 //  Created by Brendan Chen on 2025.08.09.
 //
 
-import SwiftUI
 import SwiftData
+import SwiftUI
 
 @main
 struct SeveredApp: App {
-    var sharedModelContainer: ModelContainer = {
-        let schema = Schema([
-            Item.self,
-        ])
-        let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false)
+    private let container: ModelContainer
+    @State private var authorization: ScreenTimeAuthorization
+    @State private var enforcer: RuleEnforcer
 
+    init() {
+        let config = LaunchConfiguration.current
+
+        if let onboardingCompleted = config.onboardingCompleted {
+            UserDefaults.standard.set(onboardingCompleted, forKey: "hasCompletedOnboarding")
+        }
+
+        let schema = Schema([BlockingRule.self])
+        let modelConfiguration = ModelConfiguration(
+            schema: schema, isStoredInMemoryOnly: config.isUITesting
+        )
         do {
-            return try ModelContainer(for: schema, configurations: [modelConfiguration])
+            container = try ModelContainer(for: schema, configurations: [modelConfiguration])
         } catch {
             fatalError("Could not create ModelContainer: \(error)")
         }
-    }()
+
+        if let scenario = config.seedScenario {
+            SampleRules.seed(scenario, into: container.mainContext)
+        }
+
+        let authProvider: AuthorizationProviding =
+            config.isUITesting
+            ? MockAuthorizationProvider(
+                status: config.onboardingCompleted == false ? .notDetermined : .approved
+            )
+            : FamilyControlsAuthorizationProvider()
+        _authorization = State(initialValue: ScreenTimeAuthorization(provider: authProvider))
+
+        let shields: ShieldApplying =
+            config.isUITesting ? MockShieldController() : ManagedSettingsShieldController()
+        _enforcer = State(initialValue: RuleEnforcer(shields: shields))
+    }
 
     var body: some Scene {
         WindowGroup {
-            ContentView()
+            RootView()
+                .environment(authorization)
+                .environment(enforcer)
+                .preferredColorScheme(.dark)
+                .tint(Theme.accent)
         }
-        .modelContainer(sharedModelContainer)
+        .modelContainer(container)
     }
 }