TASK 20 step 2: hotkey config UI + modifier chord persistence + conflict detection

Services/GlobalHotkeys.cs

@@ -22,14 +22,14 @@ public enum HotkeyId
 /// user32 (a real registration is global to the machine and needs a pump).</summary>
 public interface IHotkeyRegistrar
 {
-    bool Register(IntPtr hwnd, HotkeyId id, uint virtualKey);
+    bool Register(IntPtr hwnd, HotkeyId id, uint modifiers, uint virtualKey);
     void Unregister(IntPtr hwnd, HotkeyId id);
 }
 
 public sealed class Win32HotkeyRegistrar : IHotkeyRegistrar
 {
-    public bool Register(IntPtr hwnd, HotkeyId id, uint virtualKey)
-        => RegisterHotKey(hwnd, (int)id, 0, virtualKey);
+    public bool Register(IntPtr hwnd, HotkeyId id, uint modifiers, uint virtualKey)
+        => RegisterHotKey(hwnd, (int)id, modifiers, virtualKey);
 
     public void Unregister(IntPtr hwnd, HotkeyId id)
         => UnregisterHotKey(hwnd, (int)id);
@@ -46,6 +46,7 @@ public sealed class Win32HotkeyRegistrar : IHotkeyRegistrar
 /// Defaults: F1-F5 stage/transition the five canonical scenes, F6 start/end stream,
 /// F7 mute mic, F8 mute desktop audio, F9 TRAX play/pause.
 /// Attach after the window has a source (OnSourceInitialized); Detach on close.
+/// Pass a custom bindings dictionary to override defaults.
 /// </summary>
 public sealed class GlobalHotkeyManager
 {
@@ -53,17 +54,17 @@ public sealed class GlobalHotkeyManager
 
     internal static Func<IHotkeyRegistrar>? RegistrarOverride;
 
-    private static readonly Dictionary<HotkeyId, uint> Defaults = new()
+    internal static readonly Dictionary<HotkeyId, HotkeyChord> Defaults = new()
     {
-        [HotkeyId.SceneStarting] = 0x70, // F1
-        [HotkeyId.SceneLive] = 0x71,     // F2
-        [HotkeyId.SceneBrb] = 0x72,      // F3
-        [HotkeyId.SceneChat] = 0x73,     // F4
-        [HotkeyId.SceneEnding] = 0x74,   // F5
-        [HotkeyId.StartStopStream] = 0x75, // F6
-        [HotkeyId.ToggleMicMute] = 0x76,   // F7
-        [HotkeyId.ToggleGameMute] = 0x77,  // F8
-        [HotkeyId.TraxPlayPause] = 0x78,   // F9
+        [HotkeyId.SceneStarting]  = new HotkeyChord(0, 0x70), // F1
+        [HotkeyId.SceneLive]      = new HotkeyChord(0, 0x71), // F2
+        [HotkeyId.SceneBrb]       = new HotkeyChord(0, 0x72), // F3
+        [HotkeyId.SceneChat]      = new HotkeyChord(0, 0x73), // F4
+        [HotkeyId.SceneEnding]    = new HotkeyChord(0, 0x74), // F5
+        [HotkeyId.StartStopStream]= new HotkeyChord(0, 0x75), // F6
+        [HotkeyId.ToggleMicMute]  = new HotkeyChord(0, 0x76), // F7
+        [HotkeyId.ToggleGameMute] = new HotkeyChord(0, 0x77), // F8
+        [HotkeyId.TraxPlayPause]  = new HotkeyChord(0, 0x78), // F9
     };
 
     private readonly IHotkeyRegistrar _registrar;
@@ -81,22 +82,52 @@ public sealed class GlobalHotkeyManager
 
     internal GlobalHotkeyManager(IHotkeyRegistrar registrar) => _registrar = registrar;
 
-    public void Attach(System.Windows.Window window)
+    /// <summary>
+    /// Attach to a window and register hotkeys. If <paramref name="bindings"/> is
+    /// non-null, it overrides the defaults for the provided entries; any HotkeyId
+    /// not present in the dictionary falls back to the built-in default.
+    /// </summary>
+    public void Attach(System.Windows.Window window, Dictionary<HotkeyId, HotkeyChord>? bindings = null)
     {
         _hwnd = new System.Windows.Interop.WindowInteropHelper(window).Handle;
         _source = System.Windows.Interop.HwndSource.FromHwnd(_hwnd);
         _source?.AddHook(WndProc);
-        foreach (var (id, vk) in Defaults)
-        {
-            if (_registrar.Register(_hwnd, id, vk))
-                _registered.Add(id);
-            else
-                AppLog.Write($"Hotkey: {(HotkeyId)id} (vk {vk}) not registered — likely owned by another app");
-        }
+        RegisterAll(bindings);
         window.Closed += OnWindowClosed;
         AppLog.Write($"hotkey: attached, {_registered.Count} registered");
     }
 
+    /// <summary>
+    /// Hot-swap bindings: detach current registrations, re-register with new
+    /// bindings. Call after the user saves custom hotkey config.
+    /// </summary>
+    public void Reattach(System.Windows.Window window, Dictionary<HotkeyId, HotkeyChord> bindings)
+    {
+        Detach();
+        _hwnd = new System.Windows.Interop.WindowInteropHelper(window).Handle;
+        _source = System.Windows.Interop.HwndSource.FromHwnd(_hwnd);
+        _source?.AddHook(WndProc);
+        RegisterAll(bindings);
+        AppLog.Write($"hotkey: reattached, {_registered.Count} registered");
+    }
+
+    private void RegisterAll(Dictionary<HotkeyId, HotkeyChord>? bindings)
+    {
+        foreach (HotkeyId id in Enum.GetValues(typeof(HotkeyId)))
+        {
+            var chord = bindings != null && bindings.TryGetValue(id, out var custom)
+                ? custom
+                : Defaults.TryGetValue(id, out var def) ? def : null;
+
+            if (chord == null) continue; // unbound action
+
+            if (_registrar.Register(_hwnd, id, chord.Modifiers, chord.VirtualKey))
+                _registered.Add(id);
+            else
+                AppLog.Write($"Hotkey: {id} ({chord.ToDisplayString()}) not registered — likely owned by another app");
+        }
+    }
+
     private void OnWindowClosed(object? sender, EventArgs e) => Detach();
 
     private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
@@ -110,7 +141,7 @@ public sealed class GlobalHotkeyManager
         return IntPtr.Zero;
     }
 
-    private void Detach()
+    public void Detach()
     {
         if (_hwnd != IntPtr.Zero)
             foreach (var id in _registered)