Refactoring

Sources/DataRaft/Extensions/Notification+UserInfoKey.swift

@@ -0,0 +1,33 @@
+import Foundation
+
+extension Notification {
+    /// A strongly typed key used to access values in a notification’s user info dictionary.
+    ///
+    /// ## Overview
+    ///
+    /// `UserInfoKey` provides type safety when working with `Notification.userInfo`, replacing raw
+    /// string literals with well-defined constants. This helps prevent typos and improves
+    /// discoverability in database- or system-related notifications.
+    ///
+    /// ## Topics
+    ///
+    /// ### Keys
+    ///
+    /// - ``action``
+    public struct UserInfoKey: RawRepresentable, Hashable, Sendable {
+        /// The raw string value of the key.
+        public let rawValue: String
+        
+        /// The key used to store the action associated with a notification.
+        public static let action = Self(rawValue: "action")
+        
+        /// Creates a user info key from the provided raw string value.
+        ///
+        /// Returns `nil` if the raw value is invalid.
+        ///
+        /// - Parameter rawValue: The raw string value of the key.
+        public init?(rawValue: String) {
+            self.rawValue = rawValue
+        }
+    }
+}

Sources/DataRaft/Extensions/NotificationCenter.swift

@@ -0,0 +1,9 @@
+import Foundation
+
+public extension NotificationCenter {
+    /// The notification center dedicated to database events.
+    ///
+    /// Use this instance to post and observe notifications related to database lifecycle and
+    /// operations instead of using the shared `NotificationCenter.default`.
+    static let database = NotificationCenter()
+}