feat: add widget extension — small, medium, large

- KisaniCalWidget: 3 sizes sharing the app's design language
  Small: date badge + kisaniCAL. wordmark + task count
  Medium: badge + task list (3 items) + workout row
  Large: badge + full task list (6 items) + workout row

- WidgetDataStore (Shared/): lightweight Codable types for App Group
  UserDefaults cross-process data exchange

- WidgetBridge: TaskViewModel/WorkoutViewModel extensions that sync
  data into App Group and call WidgetCenter.reloadAllTimelines()

- ContentView: calls syncWidget() on appear and scene becoming active

- project.yml + entitlements updated; project regenerated via xcodegen

KisaniCal/WidgetBridge.swift

@@ -0,0 +1,41 @@
+import WidgetKit
+
+// Syncs app ViewModels into App Group UserDefaults so the widget can read them,
+// then asks WidgetKit to reload all timelines.
+
+extension TaskViewModel {
+    func syncWidget() {
+        let cal   = Calendar.current
+        let start = cal.startOfDay(for: Date())
+        let end   = cal.date(byAdding: .day, value: 1, to: start)!
+
+        let entries = tasks
+            .filter { !$0.isComplete }
+            .prefix(10)
+            .map { t in
+                WidgetDataStore.WidgetTask(
+                    id:        t.id,
+                    title:     t.title,
+                    dueDate:   t.dueDate,
+                    isToday:   t.dueDate.map { $0 >= start && $0 < end } ?? false,
+                    isOverdue: t.dueDate.map { $0 < start } ?? false
+                )
+            }
+        WidgetDataStore.saveTasks(Array(entries))
+        WidgetCenter.shared.reloadAllTimelines()
+    }
+}
+
+extension WorkoutViewModel {
+    func syncWidget() {
+        let weekday = Calendar.current.component(.weekday, from: Date())
+        let todayProgram = program(for: Date())
+        let workout = WidgetDataStore.WidgetWorkout(
+            name:            activeProgram?.name ?? "Workout",
+            sectionsCount:   activeProgram?.sections.count ?? 0,
+            hasWorkoutToday: todayProgram != nil
+        )
+        WidgetDataStore.saveWorkout(workout)
+        WidgetCenter.shared.reloadAllTimelines()
+    }
+}