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>

composeApp/src/commonMain/kotlin/com/example/casera/viewmodel/TaskCompletionViewModel.kt

@@ -2,11 +2,11 @@ package com.example.casera.viewmodel
 
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import com.example.casera.data.DataManager
 import com.example.casera.models.TaskCompletion
 import com.example.casera.models.TaskCompletionCreateRequest
 import com.example.casera.network.ApiResult
 import com.example.casera.network.TaskCompletionApi
-import com.example.casera.storage.TokenStorage
 import com.example.casera.util.ImageCompressor
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
@@ -21,7 +21,7 @@ class TaskCompletionViewModel : ViewModel() {
     fun createTaskCompletion(request: TaskCompletionCreateRequest) {
         viewModelScope.launch {
             _createCompletionState.value = ApiResult.Loading
-            val token = TokenStorage.getToken()
+            val token = DataManager.authToken.value
             if (token != null) {
                 _createCompletionState.value = taskCompletionApi.createCompletion(token, request)
             } else {
@@ -42,7 +42,7 @@ class TaskCompletionViewModel : ViewModel() {
     ) {
         viewModelScope.launch {
             _createCompletionState.value = ApiResult.Loading
-            val token = TokenStorage.getToken()
+            val token = DataManager.authToken.value
             if (token != null) {
                 // Compress images and prepare for upload
                 val compressedImages = images.map { ImageCompressor.compressImage(it) }