feature: user-selectable capture hotkey with recorder in Settings

Sources/Shotdeck/AppModel.swift

@@ -1,5 +1,4 @@
 import AppKit
-import Carbon.HIToolbox
 import Foundation
 import Observation
 import SwiftUI
@@ -37,6 +36,9 @@ public final class AppModel {
     public private(set) var outboxURL: URL
     /// Live watch folder; WP-4c updates this alongside `ReturnWatcher.updateWatchFolder`.
     public private(set) var watchFolderURL: URL
+    /// Currently bound capture combo (the last one Carbon accepted, or the preferred load).
+    private(set) var captureHotkey: HotkeyPreference
+    var hotkeyDisplayString: String { captureHotkey.displayString }
 
     let paths: AppSupportPaths
     let spool: SpoolStore
@@ -80,6 +82,7 @@ public final class AppModel {
         self.watchFolderURL = folders.watch
         self.outboxDisplayName = folders.outbox.lastPathComponent
         self.watchFolderDisplayName = folders.watch.lastPathComponent
+        self.captureHotkey = HotkeyPreference.load()
     }
 
     // MARK: Seam mutators — the only way a WP-4b/4c extension changes state.
@@ -146,16 +149,39 @@ public final class AppModel {
             setStatus((error as? ShotdeckError)?.errorDescription ?? "Could not watch the return folder.")
         }
 
-        let registered = hotkeys.register(
+        let pref = HotkeyPreference.load()
+        captureHotkey = pref
+        if !bindCaptureHotkey(pref) {
+            setStatus("\(pref.displayString) is already used by another app — capture only works from the menu.")
+        }
+    }
+
+    /// Unregisters `capture` and binds `HotkeyPreference.load()`. If Carbon rejects the new
+    /// combo, restores the previous preference (UserDefaults + Carbon) so the old one keeps working.
+    func reRegisterHotkey() {
+        let previous = captureHotkey
+        let next = HotkeyPreference.load()
+        hotkeys.unregister(id: "capture")
+        if bindCaptureHotkey(next) {
+            captureHotkey = next
+            return
+        }
+        setStatus("That combination is taken — pick another.")
+        previous.save()
+        if bindCaptureHotkey(previous) {
+            captureHotkey = previous
+        }
+    }
+
+    @discardableResult
+    private func bindCaptureHotkey(_ pref: HotkeyPreference) -> Bool {
+        hotkeys.register(
             id: "capture",
-            keyCode: UInt32(kVK_ANSI_2),
-            modifiers: UInt32(optionKey | shiftKey)
+            keyCode: pref.keyCode,
+            modifiers: pref.modifiers
         ) { [weak self] in
             Task { await self?.captureNow() }
         }
-        if !registered {
-            setStatus("⌥⇧2 is already used by another app — capture only works from the menu.")
-        }
     }
 
     public func captureNow() async {