Fix safety issues, deprecated APIs, and code quality improvements

- Replace force unwrap developer.tornID! with safe optional binding
- Generate travel notification IDs dynamically from TravelNotificationSetting.defaults
  instead of hardcoded strings, preventing cancellation gaps
- Extract duplicated developer ID (2362436) into TornConstants enum
- Change DateFormatter from computed property to static let to avoid
  expensive re-creation on every render
- Remove redundant objectWillChange.send() already handled by @Published
- Migrate deprecated onChange(of:) { _ in } to new parameterless closure form

MacTorn/MacTorn/MacTornApp.swift

@@ -14,7 +14,7 @@ struct MacTornApp: App {
                 .onAppear {
                     updateAppearance()
                 }
-                .onChange(of: appearanceModeRaw) { _ in
+                .onChange(of: appearanceModeRaw) {
                     updateAppearance()
                 }
         } label: {

MacTorn/MacTorn/Models/TornModels.swift

@@ -1,6 +1,11 @@
 import Foundation
 import SwiftUI
 
+// MARK: - Constants
+enum TornConstants {
+    static let developerID = 2362436
+}
+
 // MARK: - Root Response
 struct TornResponse: Codable {
     let name: String?

MacTorn/MacTorn/Utilities/NotificationManager.swift

@@ -103,14 +103,8 @@ class NotificationManager: NSObject, UNUserNotificationCenterDelegate {
 
     /// Cancel all travel-related notifications
     func cancelTravelNotifications() {
-        let identifiers = [
-            "travel_2min_alert",
-            "travel_1min_alert",
-            "travel_30sec_alert",
-            "travel_10sec_alert"
-        ]
+        let identifiers = TravelNotificationSetting.defaults.map { "\($0.id)_alert" }
         UNUserNotificationCenter.current().removePendingNotificationRequests(withIdentifiers: identifiers)
-        print("Cancelled travel notifications")
     }
 
     /// Cancel a specific notification by identifier

MacTorn/MacTorn/ViewModels/AppState.swift

@@ -584,9 +584,7 @@ class AppState: ObservableObject {
             // Check if feedback prompt should be shown
             self.checkFeedbackPrompt()
 
-            // Force UI update by triggering objectWillChange
-            self.objectWillChange.send()
-            logger.info("UI update triggered, lastUpdated: \(self.lastUpdated?.description ?? "nil")")
+            logger.info("Data updated, lastUpdated: \(self.lastUpdated?.description ?? "nil")")
         }
     }
     

MacTorn/MacTorn/Views/ContentView.swift

@@ -91,7 +91,7 @@ struct ContentView: View {
     private var headerView: some View {
         HStack {
             if let lastUpdated = appState.lastUpdated {
-                Text("Updated: \(lastUpdated, formatter: timeFormatter)")
+                Text("Updated: \(lastUpdated, formatter: Self.timeFormatter)")
                     .font(.caption2)
                     .foregroundColor(.secondary)
             }
@@ -177,9 +177,9 @@ struct ContentView: View {
         .padding(.bottom, 8)
     }
     
-    private var timeFormatter: DateFormatter {
+    private static let timeFormatter: DateFormatter = {
         let formatter = DateFormatter()
         formatter.timeStyle = .short
         return formatter
-    }
+    }()
 }

MacTorn/MacTorn/Views/CreditsView.swift

@@ -5,7 +5,7 @@ struct CreditsView: View {
     @Binding var showCredits: Bool
 
     // MARK: - Developer
-    private let developer = TornContributor(name: "bombel", tornID: 2362436)
+    private let developer = TornContributor(name: "bombel", tornID: TornConstants.developerID)
 
     // MARK: - Special Thanks
     private let specialThanks: [TornContributor] = [
@@ -92,7 +92,9 @@ struct CreditsView: View {
             }
 
             Button {
-                openTornProfile(developer.tornID!)
+                if let tornID = developer.tornID {
+                    openTornProfile(tornID)
+                }
             } label: {
                 HStack {
                     Text(developer.name)

MacTorn/MacTorn/Views/SettingsView.swift

@@ -9,8 +9,7 @@ struct SettingsView: View {
     @State private var showCredits: Bool = false
     @State private var availableBrowsers: [PreferredBrowser] = PreferredBrowser.availableBrowsers()
 
-    // Developer ID for tip feature (bombel)
-    private let developerID = 2362436
+    private let developerID = TornConstants.developerID
 
     var body: some View {
         if showCredits {
@@ -74,7 +73,7 @@ struct SettingsView: View {
                         Text("2m").tag(120)
                     }
                     .pickerStyle(.segmented)
-                    .onChange(of: appState.refreshInterval) { _ in
+                    .onChange(of: appState.refreshInterval) {
                         Task { @MainActor in
                             appState.startPolling()
                         }