feat: implement core notification functionality for iOS and Android - Add settings management, proper error handling, and platform-specific implementations

ios/Plugin/DailyNotificationConstants.swift

@@ -0,0 +1,52 @@
+/**
+ * DailyNotificationConstants.swift
+ * Daily Notification Plugin for Capacitor
+ *
+ * Defines constant values used throughout the notification plugin
+ */
+
+import Foundation
+
+/// Constants used throughout the DailyNotification plugin
+///
+/// This structure provides centralized access to all constant values used in the plugin,
+/// making it easier to maintain and update common values.
+public struct DailyNotificationConstants {
+    /// Default notification title when none is provided
+    public static let defaultTitle = "Daily Notification"
+    
+    /// Default notification body when none is provided
+    public static let defaultBody = "Your daily update is ready"
+    
+    /// Prefix used for notification identifiers
+    public static let notificationIdentifierPrefix = "daily-notification-"
+    
+    /// Name of the event emitted for notification interactions
+    public static let eventName = "notification"
+    
+    /// Default settings for notifications
+    public struct Settings {
+        /// Whether sound is enabled by default
+        public static let defaultSound = true
+        
+        /// Default priority level for notifications
+        public static let defaultPriority = "default"
+        
+        /// Default number of retry attempts
+        public static let defaultRetryCount = 3
+        
+        /// Default interval between retries (in milliseconds)
+        public static let defaultRetryInterval = 1000
+    }
+    
+    /// Keys used in plugin method calls
+    public struct Keys {
+        public static let url = "url"
+        public static let time = "time"
+        public static let title = "title"
+        public static let body = "body"
+        public static let sound = "sound"
+        public static let priority = "priority"
+        public static let timezone = "timezone"
+    }
+}