Fix covers getting deleted in macOS 15

UserNotifications now deletes the attachments on macOS 15 (or did
before, and instead of us never triggering, does so automatically).

Regardless, this is not good for us. Instead of using the image on disk
we use for everything else, make a copy instead in the temporary
directory. On >=15, it'll delete that, and before that, it should get
cleaned automatically anyways.

README.md

@@ -37,6 +37,7 @@ Doing so isn't fatal (it's not a secret), but it is annoying for other contribut
     * Top tracks for an artist can now be displayed
     * Similar tracks for an artist (sometimes called "radio") can now be displayed
 * Directories can be starred.
+* Fix covers being deleted by the system on macOS 15.
 * Fix searches being ran twice.
 * Fix albums with the same ID across multiple servers being mixed.
 

Submariner/SBPlayer.swift

@@ -393,8 +393,15 @@ extension NSNotification.Name {
             // This means there's also a bunch of empty dupe cover objects in the DB...
             if let newCover = currentTrack.album?.cover, let coverPath = newCover.imagePath {
                 let coverURL = URL(fileURLWithPath: coverPath as String)
-                if let attachment = try? UNNotificationAttachment(identifier: "", url: coverURL) {
+                // macOS 15 starts deleting attachment files; make a copy in temp dir to avoid this fate
+                let tempURL = URL.temporaryFile(fileExtension: coverURL.pathExtension)
+                do {
+                    try FileManager.default.copyItem(at: coverURL,
+                                                      to: tempURL)
+                    let attachment = try UNNotificationAttachment(identifier: "", url: tempURL)
                     content.attachments = [attachment]
+                } catch {
+                    // if we fail, then just skip making an attachment
                 }
             }
 

Submariner/URL+Parameters.swift

@@ -15,9 +15,13 @@ extension URL {
     // #MARK: -
     // #MARK: Temporary Files
 
-    static func temporaryFile() -> URL {
+    static func temporaryFile(fileExtension: String? = nil) -> URL {
         let tempDir = FileManager.default.temporaryDirectory
-        let randomName = UUID().uuidString
+        var randomName = UUID().uuidString
+        // better to use the UTType appendingPathExtension if possible
+        if let fileExtension = fileExtension, !fileExtension.isEmpty {
+            randomName += ".\(fileExtension)"
+        }
         return tempDir.appendingPathComponent(randomName)
     }