Add optional clipboard capture sounds

Copy/App/AppCoordinator.swift

@@ -381,6 +381,7 @@ final class AppCoordinator {
                             // Already on the main queue; hop into main-actor isolation for
                             // the one-time activation nudges (see the methods).
                             MainActor.assumeIsolated {
+                                CopySoundPlayer.shared.play(settings.copySound)
                                 AppCoordinator.showFirstCopyCoachIfNeeded()
                                 if !pasteStackModel.isActive {
                                     AppCoordinator.notePasteStackOpportunity()
@@ -616,6 +617,9 @@ final class AppCoordinator {
         }
         pasteService.place(reps, plainTextOnly: false)
         try? store.touch(itemID: id)
+        // The monitor ignores our own marked write, so the capture path below never
+        // sees this copy and the feedback has to be asked for here.
+        CopySoundPlayer.shared.play(settings.copySound)
         return true
     }
 

Copy/Settings/GeneralSettings.swift

@@ -55,6 +55,28 @@ struct GeneralSettings: View {
                     .foregroundStyle(.secondary)
             }
 
+            Section {
+                HStack {
+                    Text("Copy Sound")
+                    Spacer()
+                    Picker("Copy Sound", selection: $settings.copySound) {
+                        ForEach(CopySound.allCases) { sound in
+                            Text(sound.title).tag(sound)
+                        }
+                    }
+                    .labelsHidden()
+                    .pickerStyle(.menu)
+                    .frame(width: 120)
+                }
+                .onChange(of: settings.copySound) { _, sound in
+                    CopySoundPlayer.shared.play(sound)
+                }
+            } footer: {
+                Text("Plays after Copy captures a new clipboard item.")
+                    .font(.footnote)
+                    .foregroundStyle(.secondary)
+            }
+
             Section {
                 Toggle("Launch at Login", isOn: launchAtLoginBinding)
             } footer: {

Copy/Settings/SettingsStore.swift

@@ -1,6 +1,35 @@
+import AppKit
 import Foundation
 import Observation
 
+/// Optional feedback played after Copy successfully records a clipboard change.
+/// Raw values are persisted in UserDefaults, so keep them stable across releases.
+/// Each case names a sound macOS ships in `/System/Library/Sounds`; adding another of
+/// those (Bottle, Glass, Morse, Purr...) is one case here and nothing else.
+enum CopySound: String, CaseIterable, Identifiable {
+    case off
+    case pop
+    case tink
+
+    var id: Self { self }
+
+    var title: String {
+        switch self {
+        case .off: return "Off"
+        case .pop: return "Pop"
+        case .tink: return "Tink"
+        }
+    }
+
+    var systemSoundName: NSSound.Name? {
+        switch self {
+        case .off: return nil
+        case .pop: return "Pop"
+        case .tink: return "Tink"
+        }
+    }
+}
+
 /// How long unfavorited, unpinned history items are kept before pruning.
 enum RetentionPeriod: String, CaseIterable {
     case unlimited
@@ -57,6 +86,7 @@ final class SettingsStore {
     static let shelfProDarkKey = "shelfProDark"
     static let hideMenuBarIconKey = "hideMenuBarIcon"
     static let doubleClickToPasteKey = "doubleClickToPaste"
+    static let copySoundKey = "copySound"
 
     var retention: RetentionPeriod {
         didSet {
@@ -154,6 +184,15 @@ final class SettingsStore {
         }
     }
 
+    /// Sound feedback for successful clipboard captures. Off is the intentional
+    /// default so installing or updating Copy never adds noise without consent.
+    var copySound: CopySound {
+        didSet {
+            guard copySound != oldValue else { return }
+            defaults.set(copySound.rawValue, forKey: Self.copySoundKey)
+        }
+    }
+
     @ObservationIgnored var onRulesChange: ((Set<String>) -> Void)?
     /// Fired by the About pane's "Check for Updates…" button. Bridged to Sparkle's
     /// `updaterController` in `AppDelegate` (which owns it), so this store — and the
@@ -191,6 +230,8 @@ final class SettingsStore {
         shelfProDark = (defaults.object(forKey: Self.shelfProDarkKey) as? Bool) ?? false
         hideMenuBarIcon = (defaults.object(forKey: Self.hideMenuBarIconKey) as? Bool) ?? false
         doubleClickToPaste = (defaults.object(forKey: Self.doubleClickToPasteKey) as? Bool) ?? true
+        copySound = defaults.string(forKey: Self.copySoundKey)
+            .flatMap(CopySound.init(rawValue:)) ?? .off
         if let data = defaults.data(forKey: Self.excludedBundleIDsKey),
            let decoded = try? JSONDecoder().decode([String].self, from: data) {
             excludedBundleIDs = decoded.sorted()

Copy/Support/CopySoundPlayer.swift

@@ -0,0 +1,35 @@
+import AppKit
+
+/// Plays the optional feedback for a clipboard capture. The sounds are the ones macOS
+/// already ships in `/System/Library/Sounds`, so Copy bundles no audio of its own: a
+/// stock-audio licence that permits redistribution from a public GPL repository is hard
+/// to satisfy (both Pixabay and Mixkit forbid handing their files over on their own, and
+/// a file in this repo is downloadable on its own), and a system sound already follows
+/// the listener's output device and alert volume.
+@MainActor
+final class CopySoundPlayer {
+    static let shared = CopySoundPlayer()
+
+    private var cache: [CopySound: NSSound] = [:]
+    private var playing: NSSound?
+
+    private init() {}
+
+    func play(_ choice: CopySound) {
+        // A burst of copies should sound like the latest one, not like all of them.
+        playing?.stop()
+        playing = nil
+
+        guard let name = choice.systemSoundName else { return }
+        let sound: NSSound
+        if let cached = cache[choice] {
+            sound = cached
+        } else {
+            guard let loaded = NSSound(named: name) else { return }
+            cache[choice] = loaded
+            sound = loaded
+        }
+        playing = sound
+        sound.play()
+    }
+}