Implement Android subscription system with freemium limitations

Major subscription system implementation for Android:

BillingManager (Android):
- Full Google Play Billing Library integration
- Product loading, purchase flow, and acknowledgment
- Backend verification via APILayer.verifyAndroidPurchase()
- Purchase restoration for returning users
- Error handling and connection state management

SubscriptionHelper (Shared):
- New limit checking methods: isResidencesBlocked(), isTasksBlocked(),
  isContractorsBlocked(), isDocumentsBlocked()
- Add permission checks: canAddProperty(), canAddTask(),
  canAddContractor(), canAddDocument()
- Enforces freemium rules based on backend limitationsEnabled flag

Screen Updates:
- ContractorsScreen: Show upgrade prompt when contractors limit=0
- DocumentsScreen: Show upgrade prompt when documents limit=0
- ResidencesScreen: Show upgrade prompt when properties limit reached
- ResidenceDetailScreen: Show upgrade prompt when tasks limit reached

UpgradeFeatureScreen:
- Enhanced with feature benefits comparison
- Dynamic content from backend upgrade triggers
- Platform-specific purchase buttons

Additional changes:
- DataCache: Added O(1) lookup maps for ID resolution
- New minimal models (TaskMinimal, ContractorMinimal, ResidenceMinimal)
- TaskApi: Added archive/unarchive endpoints
- Added Google Billing Library dependency
- iOS SubscriptionCache and UpgradePromptView updates

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

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

composeApp/src/commonMain/kotlin/com/example/mycrib/models/CustomTask.kt

@@ -112,6 +112,37 @@ data class TaskCancelResponse(
     val task: TaskDetail
 )
 
+/**
+ * Request model for PATCH updates to a task.
+ * Used for status changes and archive/unarchive operations.
+ * All fields are optional - only provided fields will be updated.
+ */
+@Serializable
+data class TaskPatchRequest(
+    val status: Int? = null,    // Status ID to update
+    val archived: Boolean? = null  // Archive/unarchive flag
+)
+
+/**
+ * Minimal task model for list/kanban views.
+ * Uses IDs instead of nested objects for efficiency.
+ * Resolve IDs to full objects via DataCache.getTaskCategory(), etc.
+ */
+@Serializable
+data class TaskMinimal(
+    val id: Int,
+    val title: String,
+    val description: String? = null,
+    @SerialName("due_date") val dueDate: String? = null,
+    @SerialName("next_scheduled_date") val nextScheduledDate: String? = null,
+    @SerialName("category_id") val categoryId: Int? = null,
+    @SerialName("frequency_id") val frequencyId: Int,
+    @SerialName("priority_id") val priorityId: Int,
+    @SerialName("status_id") val statusId: Int? = null,
+    @SerialName("completion_count") val completionCount: Int? = null,
+    val archived: Boolean = false
+)
+
 @Serializable
 data class TaskColumn(
     val name: String,
@@ -119,7 +150,7 @@ data class TaskColumn(
     @SerialName("button_types") val buttonTypes: List<String>,
     val icons: Map<String, String>,
     val color: String,
-    val tasks: List<TaskDetail>,
+    val tasks: List<TaskDetail>,  // Keep using TaskDetail for now - will be TaskMinimal after full migration
     val count: Int
 )