Consolidate task metrics to single source of truth

- Add API column name constants to WidgetDataManager (overdueColumn,
  dueWithin7DaysColumn, due8To30DaysColumn, etc.)
- Update DataManagerObservable to use WidgetDataManager column constants
- Remove duplicate ResidenceTaskStats struct, use TaskMetrics everywhere
- Delete TaskStatsCalculator.swift (consolidated into WidgetDataManager)
- Rename confusing flags: isUpcoming → isDueWithin7Days, isLater → isDue8To30Days
- Add comprehensive unit tests for TaskMetrics and WidgetTask

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

iosApp/iosApp/Residence/ResidencesListView.swift

@@ -23,10 +23,7 @@ struct ResidencesListView: View {
                     isLoading: viewModel.isLoading,
                     errorMessage: viewModel.errorMessage,
                     content: { residences in
-                        ResidencesContent(
-                            residences: residences,
-                            tasksResponse: taskViewModel.tasksResponse
-                        )
+                        ResidencesContent(residences: residences)
                     },
                     emptyContent: {
                         OrganicEmptyResidencesView()
@@ -170,67 +167,28 @@ private struct OrganicToolbarButton: View {
     }
 }
 
-// MARK: - Residence Task Stats
-struct ResidenceTaskStats {
-    let totalCount: Int
-    let overdueCount: Int
-    let dueThisWeekCount: Int
-    let dueNext30DaysCount: Int
-}
-
 // MARK: - Residences Content View
 
 private struct ResidencesContent: View {
     let residences: [ResidenceResponse]
-    let tasksResponse: TaskColumnsResponse?
+    @ObservedObject private var dataManager = DataManagerObservable.shared
 
-    /// Extract active tasks - skip completed_tasks and cancelled_tasks columns
-    private var activeTasks: [TaskResponse] {
-        guard let response = tasksResponse else { return [] }
-
-        var tasks: [TaskResponse] = []
-        for column in response.columns {
-            // Skip completed and cancelled columns (cancelled includes archived)
-            let columnName = column.name.lowercased()
-            if columnName == "completed_tasks" || columnName == "cancelled_tasks" {
-                continue
-            }
-
-            // Add tasks from this column
-            for task in column.tasks {
-                tasks.append(task)
-            }
-        }
-        return tasks
-    }
-
-    /// Compute total summary from task data using shared TaskStatsCalculator
+    /// Compute total summary from DataManagerObservable (single source of truth)
     private var computedSummary: TotalSummary {
-        let dueDates = activeTasks.map { $0.effectiveDueDate }
-        let stats = TaskStatsCalculator.calculate(from: dueDates)
-
+        let metrics = dataManager.totalTaskMetrics
         return TotalSummary(
             totalResidences: Int32(residences.count),
-            totalTasks: Int32(activeTasks.count),
+            totalTasks: Int32(dataManager.activeTasks.count),
             totalPending: 0,
-            totalOverdue: Int32(stats.overdueCount),
-            tasksDueNextWeek: Int32(stats.next7DaysCount),
-            tasksDueNextMonth: Int32(stats.next30DaysCount)
+            totalOverdue: Int32(metrics.overdueCount),
+            tasksDueNextWeek: Int32(metrics.upcoming7Days),
+            tasksDueNextMonth: Int32(metrics.upcoming30Days)
         )
     }
 
-    /// Get task stats for a specific residence using shared TaskStatsCalculator
-    private func taskStats(for residenceId: Int32) -> ResidenceTaskStats {
-        let residenceTasks = activeTasks.filter { $0.residenceId == residenceId }
-        let dueDates = residenceTasks.map { $0.effectiveDueDate }
-        let stats = TaskStatsCalculator.calculate(from: dueDates)
-
-        return ResidenceTaskStats(
-            totalCount: residenceTasks.count,
-            overdueCount: stats.overdueCount,
-            dueThisWeekCount: stats.next7DaysCount,
-            dueNext30DaysCount: stats.next30DaysCount
-        )
+    /// Get task metrics for a specific residence from DataManagerObservable
+    private func taskMetrics(for residenceId: Int32) -> WidgetDataManager.TaskMetrics {
+        dataManager.taskMetrics(for: residenceId)
     }
 
     var body: some View {
@@ -247,7 +205,7 @@ private struct ResidencesContent: View {
                         NavigationLink(destination: ResidenceDetailView(residenceId: residence.id)) {
                             ResidenceCard(
                                 residence: residence,
-                                taskStats: taskStats(for: residence.id)
+                                taskMetrics: taskMetrics(for: residence.id)
                             )
                             .padding(.horizontal, 16)
                         }