Rename IPCMessageAction to IpcMessageAction for consistency

Renamed the IPCMessageAction class to IpcMessageAction in the PowerDisplay.Serialization namespace to follow C# naming conventions. Updated all references, including JSON source generation context, to use the new name.

.github/actions/spell-check/expect.txt

@@ -340,7 +340,7 @@ CURRENTDIR
 CURSORINFO
 cursorpos
 CURSORSHOWING
-CURSORWRAP
+cursorwrap
 customaction
 CUSTOMACTIONTEST
 CUSTOMFORMATPLACEHOLDER

src/modules/powerdisplay/PowerDisplay/Serialization/IPCMessageAction.cs

@@ -10,7 +10,7 @@ namespace PowerDisplay.Serialization
     /// IPC message wrapper for parsing action-based messages.
     /// Used in App.xaml.cs for dynamic IPC command handling.
     /// </summary>
-    internal sealed class IPCMessageAction
+    internal sealed class IpcMessageAction
     {
         [JsonPropertyName("action")]
         public string? Action { get; set; }

src/modules/powerdisplay/PowerDisplay/Serialization/JsonSourceGenerationContext.cs

@@ -16,7 +16,7 @@ namespace PowerDisplay.Serialization
     /// Note: MonitorStateFile and MonitorStateEntry are now in PowerDisplay.Lib
     /// and should be serialized using ProfileSerializationContext from the Lib.
     /// </summary>
-    [JsonSerializable(typeof(IPCMessageAction))]
+    [JsonSerializable(typeof(IpcMessageAction))]
     [JsonSerializable(typeof(PowerDisplaySettings))]
     [JsonSerializable(typeof(PowerDisplayProfiles))]
     [JsonSerializable(typeof(PowerDisplayProfile))]