feat(configmanager): add Serilog file logging to UI and create README

Configure Serilog for the ConfigManager UI application, replacing console
logging with daily rolling file logs in logs/ directory with 30-day
retention. Add shutdown handler to flush logs on exit.

NEW/src/Utils/JdeScoping.ConfigManager.Ui/App.axaml.cs

@@ -7,7 +7,8 @@ using JdeScoping.ConfigManager.Core.DependencyInjection;
 using JdeScoping.ConfigManager.Ui.Services;
 using JdeScoping.ConfigManager.Ui.ViewModels;
 using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Logging;
+using Serilog;
+using Serilog.Events;
 
 namespace JdeScoping.ConfigManager.Ui;
 
@@ -37,6 +38,9 @@ public partial class App : Avalonia.Application
             {
                 DataContext = Services.GetRequiredService<MainWindowViewModel>()
             };
+
+            // Ensure logs are flushed on exit
+            desktop.ShutdownRequested += (_, _) => Log.CloseAndFlush();
         }
 
         base.OnFrameworkInitializationCompleted();
@@ -44,10 +48,24 @@ public partial class App : Avalonia.Application
 
     private void ConfigureServices(IServiceCollection services)
     {
+        // Configure Serilog with daily rolling file
+        var logsPath = Path.Combine(AppContext.BaseDirectory, "logs");
+        Directory.CreateDirectory(logsPath);
+
+        Log.Logger = new LoggerConfiguration()
+            .MinimumLevel.Information()
+            .MinimumLevel.Override("Microsoft", LogEventLevel.Warning)
+            .MinimumLevel.Override("Avalonia", LogEventLevel.Warning)
+            .Enrich.FromLogContext()
+            .WriteTo.File(
+                path: Path.Combine(logsPath, "configmanager-.log"),
+                rollingInterval: RollingInterval.Day,
+                retainedFileCountLimit: 30,
+                outputTemplate: "{Timestamp:yyyy-MM-dd HH:mm:ss.fff zzz} [{Level:u3}] {Message:lj}{NewLine}{Exception}")
+            .CreateLogger();
+
         // Logging
-        services.AddLogging(builder => builder
-            .AddConsole()
-            .SetMinimumLevel(LogLevel.Debug));
+        services.AddLogging(builder => builder.AddSerilog(dispose: true));
 
         // Add all ConfigManager.Core services
         services.AddConfigManagerCore();