add configuration watcher implementation

Application/IO/ConfigurationWatcher.cs

@@ -0,0 +1,60 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using SharedLibraryCore;
+
+namespace IW4MAdmin.Application.IO;
+
+public sealed class ConfigurationWatcher : IDisposable
+{
+    private readonly FileSystemWatcher _watcher;
+    private readonly Dictionary<string, Action<string>> _registeredActions = new();
+
+    public ConfigurationWatcher()
+    {
+        _watcher = new FileSystemWatcher
+        {
+            Path = Path.Join(Utilities.OperatingDirectory, "Configuration"),
+            Filter = "*.json",
+            NotifyFilter = NotifyFilters.LastWrite
+        };
+
+        _watcher.Changed += WatcherOnChanged;
+        _watcher.EnableRaisingEvents = true;
+    }
+
+    public void Dispose()
+    {
+        _watcher.Changed -= WatcherOnChanged;
+        _watcher.Dispose();
+    }
+
+    public void Register(string fileName, Action<string> fileUpdated)
+    {
+        if (_registeredActions.ContainsKey(fileName))
+        {
+            return;
+        }
+
+        _registeredActions.Add(fileName, fileUpdated);
+    }
+
+    public void Unregister(string fileName)
+    {
+        if (_registeredActions.ContainsKey(fileName))
+        {
+            _registeredActions.Remove(fileName);
+        }
+    }
+
+    private void WatcherOnChanged(object sender, FileSystemEventArgs eventArgs)
+    {
+        if (!_registeredActions.ContainsKey(eventArgs.FullPath) || eventArgs.ChangeType != WatcherChangeTypes.Changed ||
+            new FileInfo(eventArgs.FullPath).Length == 0)
+        {
+            return;
+        }
+
+        _registeredActions[eventArgs.FullPath].Invoke(eventArgs.FullPath);
+    }
+}

Application/Main.cs

@@ -29,6 +29,7 @@ using Data.Helpers;
 using Integrations.Source.Extensions;
 using IW4MAdmin.Application.Alerts;
 using IW4MAdmin.Application.Extensions;
+using IW4MAdmin.Application.IO;
 using IW4MAdmin.Application.Localization;
 using IW4MAdmin.Application.Plugin;
 using IW4MAdmin.Application.Plugin.Script;