🐛 fix: resolve 11 correctness and efficiency issues from code review

Sources/Wallpaper/BingAPI.swift

@@ -27,11 +27,13 @@ struct BingImage: Codable, Hashable, Identifiable {
 enum WallpaperError: LocalizedError {
     case noImages
     case downloadFailed
+    case invalidURL
 
     var errorDescription: String? {
         switch self {
         case .noImages: return "No images found"
         case .downloadFailed: return "Failed to download image"
+        case .invalidURL: return "Invalid image URL"
         }
     }
 }

Sources/Wallpaper/PreferencesStore.swift

@@ -9,6 +9,8 @@ struct WallpaperPreferences: Codable {
 final class PreferencesStore {
     static let shared = PreferencesStore()
     private(set) var preferences = WallpaperPreferences()
+    /// Favorites in newest-first order, kept in sync on mutation so callers never re-sort
+    private(set) var sortedFavorites: [BingImage] = []
     let fileURL: URL
 
     init(fileURL: URL? = nil) {
@@ -20,12 +22,17 @@ final class PreferencesStore {
 
     func load() {
         let fm = FileManager.default
+        defer { rebuildSortedFavorites() }
         guard fm.fileExists(atPath: fileURL.path) else { return }
         do {
             let data = try Data(contentsOf: fileURL)
             preferences = try JSONDecoder().decode(WallpaperPreferences.self, from: data)
         } catch {
-            // If corrupted, start fresh
+            // Start fresh, but move the unreadable file aside first: otherwise the next
+            // save() would overwrite it and destroy every favorite and dislike for good.
+            let backupURL = fileURL.appendingPathExtension("corrupt")
+            try? fm.removeItem(at: backupURL)
+            try? fm.moveItem(at: fileURL, to: backupURL)
             preferences = WallpaperPreferences()
         }
     }
@@ -63,11 +70,13 @@ final class PreferencesStore {
     func addFavorite(_ image: BingImage) {
         guard !preferences.favorites.contains(where: { $0.startdate == image.startdate }) else { return }
         preferences.favorites.append(image)
+        rebuildSortedFavorites()
         save()
     }
 
     func removeFavorite(_ image: BingImage) {
         preferences.favorites.removeAll { $0.startdate == image.startdate }
+        rebuildSortedFavorites()
         save()
     }
 
@@ -78,4 +87,8 @@ final class PreferencesStore {
     func favoriteDates() -> Set<String> {
         Set(preferences.favorites.map(\.startdate))
     }
+
+    private func rebuildSortedFavorites() {
+        sortedFavorites = preferences.favorites.sorted { $0.startdate > $1.startdate }
+    }
 }

Sources/Wallpaper/UpdateChecker.swift

@@ -184,8 +184,11 @@ final class UpdateChecker {
     // MARK: - Semver Comparison
 
     nonisolated static func isNewer(remote: String, than current: String) -> Bool {
-        let remoteParts = remote.split(separator: ".").compactMap { Int($0) }
-        let currentParts = current.split(separator: ".").compactMap { Int($0) }
+        // Parse strictly: dropping unparseable components would shift the remaining ones
+        // into the wrong significance position (e.g. "1.beta.5" comparing 5 against minor).
+        guard let remoteParts = versionComponents(remote),
+              let currentParts = versionComponents(current)
+        else { return false }
         let count = max(remoteParts.count, currentParts.count)
         for i in 0..<count {
             let r = i < remoteParts.count ? remoteParts[i] : 0
@@ -195,6 +198,21 @@ final class UpdateChecker {
         }
         return false
     }
+
+    /// Split "1.2.3" into [1, 2, 3], tolerating a trailing pre-release suffix such as
+    /// "3-rc1". Returns nil if any component has no leading digits.
+    private nonisolated static func versionComponents(_ version: String) -> [Int]? {
+        let parts = version.split(separator: ".")
+        guard !parts.isEmpty else { return nil }
+
+        var numbers: [Int] = []
+        for part in parts {
+            let digits = part.prefix { $0.isNumber }
+            guard let value = Int(digits) else { return nil }
+            numbers.append(value)
+        }
+        return numbers
+    }
 }
 
 // MARK: - Download Progress

Sources/Wallpaper/WallpaperApp.swift

@@ -31,6 +31,9 @@ struct WallpaperApp: App {
                 toolbar
             }
             .frame(width: 320)
+            // The login item can be toggled in System Settings while we run, so re-read
+            // it every time the window opens instead of trusting the launch-time snapshot
+            .onAppear { launchAtLogin = SMAppService.mainApp.status == .enabled }
         }
         .menuBarExtraStyle(.window)
     }
@@ -330,11 +333,13 @@ struct WallpaperApp: App {
             Spacer()
 
             Button {
-                launchAtLogin.toggle()
                 do {
-                    if launchAtLogin { try SMAppService.mainApp.register() }
-                    else { try SMAppService.mainApp.unregister() }
-                } catch { launchAtLogin.toggle() }
+                    if launchAtLogin { try SMAppService.mainApp.unregister() }
+                    else { try SMAppService.mainApp.register() }
+                } catch {
+                    // Fall through — the status re-read below reports what actually happened
+                }
+                launchAtLogin = SMAppService.mainApp.status == .enabled
             } label: {
                 Image(systemName: launchAtLogin ? "checkmark.circle.fill" : "circle")
             }