Add unified DataManager as single source of truth for all app data

- Create DataManager.kt with StateFlows for all cached data:
  - Authentication (token, user)
  - Residences, tasks, documents, contractors
  - Subscription status and upgrade triggers
  - All lookup data (residence types, task categories, etc.)
  - Theme preferences and state metadata

- Add PersistenceManager with platform-specific implementations:
  - Android: SharedPreferences
  - iOS: NSUserDefaults
  - JVM: Properties file
  - WasmJS: localStorage

- Migrate APILayer to update DataManager on every API response
- Update Kotlin ViewModels to use DataManager for token access
- Deprecate LookupsRepository (delegates to DataManager)
- Create iOS DataManagerObservable Swift wrapper for SwiftUI
- Update iOS auth flow to use DataManager.isAuthenticated()

Data flow: User Action → API Call → DataManager Updated → All Screens React

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

iosApp/iosApp/Task/TaskViewModel.swift

@@ -252,7 +252,7 @@ class TaskViewModel: ObservableObject {
     ///   - residenceId: Optional residence ID to filter by. If nil, loads all tasks.
     ///   - forceRefresh: Whether to bypass cache
     func loadTasks(residenceId: Int32? = nil, forceRefresh: Bool = false) {
-        guard TokenStorage.shared.getToken() != nil else { return }
+        guard DataManager.shared.isAuthenticated() else { return }
 
         currentResidenceId = residenceId
         isLoadingTasks = true