feat: add Search MP3 action to Shazam identification alert

Opens freemp3music.org and copies "title artist" to clipboard for quick paste-and-search.

Music/ContentView.swift

@@ -257,7 +257,18 @@ struct ContentView: View {
             get: { shazam.matchedTitle != nil },
             set: { if !$0 { shazam.clearResult() } }
         )) {
-            Button("OK") { shazam.clearResult() }
+            Button("Search MP3") {
+                let query = [shazam.matchedTitle, shazam.matchedArtist]
+                    .compactMap { $0 }
+                    .joined(separator: " ")
+                NSPasteboard.general.clearContents()
+                NSPasteboard.general.setString(query, forType: .string)
+                if let url = URL(string: "https://freemp3music.org/") {
+                    NSWorkspace.shared.open(url)
+                }
+                shazam.clearResult()
+            }
+            Button("Close", role: .cancel) { shazam.clearResult() }
         } message: {
             if let title = shazam.matchedTitle {
                 Text("\(title) — \(shazam.matchedArtist ?? "Unknown Artist")")