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

Shared/WidgetDataStore.swift

@@ -0,0 +1,61 @@
+import Foundation
+
+// Shared between app and widget extension via App Group UserDefaults.
+// Types are pure Codable — no UIKit / AppColors dependency.
+
+struct WidgetDataStore {
+    static let suiteName  = "group.com.kutesir.KisaniCal"
+    static let tasksKey   = "kisani.widget.tasks"
+    static let workoutKey = "kisani.widget.workout"
+
+    // MARK: - Shared types
+
+    struct WidgetTask: Codable, Identifiable {
+        let id: UUID
+        let title: String
+        let dueDate: Date?
+        let isToday: Bool
+        let isOverdue: Bool
+    }
+
+    struct WidgetWorkout: Codable {
+        let name: String
+        let sectionsCount: Int
+        let hasWorkoutToday: Bool
+    }
+
+    // MARK: - Write (app target)
+
+    static func saveTasks(_ tasks: [WidgetTask]) {
+        guard let data = try? JSONEncoder().encode(tasks),
+              let ud   = UserDefaults(suiteName: suiteName) else { return }
+        ud.set(data, forKey: tasksKey)
+    }
+
+    static func saveWorkout(_ workout: WidgetWorkout?) {
+        guard let ud = UserDefaults(suiteName: suiteName) else { return }
+        if let workout, let data = try? JSONEncoder().encode(workout) {
+            ud.set(data, forKey: workoutKey)
+        } else {
+            ud.removeObject(forKey: workoutKey)
+        }
+    }
+
+    // MARK: - Read (widget target)
+
+    static func loadTasks() -> [WidgetTask] {
+        guard let ud   = UserDefaults(suiteName: suiteName),
+              let data = ud.data(forKey: tasksKey),
+              let list = try? JSONDecoder().decode([WidgetTask].self, from: data)
+        else { return [] }
+        return list
+    }
+
+    static func loadWorkout() -> WidgetWorkout? {
+        guard let ud      = UserDefaults(suiteName: suiteName),
+              let data    = ud.data(forKey: workoutKey),
+              let workout = try? JSONDecoder().decode(WidgetWorkout.self, from: data)
+        else { return nil }
+        return workout
+    }
+}