feat(auth): ✨ add customizable error handling

Allow custom error handling for missing authentication.
Previously, the app exited immediately if no authentication
was configured. Now, an optional error handler can be provided,
enabling platform-aware and user-friendly shutdown behavior.

Author: caunt

src/EcoFlow.Mqtt.Api/EntryPoint.cs

@@ -21,7 +21,13 @@
 builder.Services.AddHttpClient();
 builder.Services.ConfigureAnonymousHttpClient();
 builder.Services.ConfigureEcoFlowEndpoints();
-builder.Services.ConfigureEcoFlowAuthentication();
+builder.Services.ConfigureEcoFlowAuthentication(errorHandler: () =>
+{
+    if (OperatingSystem.IsWindows())
+        Console.ReadLine();
+
+    Environment.Exit(1);
+});
 builder.Services.AddSingleton<InternalHttpApi>();
 builder.Services.AddSingleton<InternalMqttApi>();
 builder.Services.AddHostedService(serviceProvider => serviceProvider.GetRequiredService<InternalMqttApi>());

src/EcoFlow.Mqtt.Api/Extensions/HostingExtensions.cs

@@ -34,7 +34,7 @@ public IServiceCollection ConfigureEcoFlowEndpoints()
             });
         }
 
-        public IServiceCollection ConfigureEcoFlowAuthentication()
+        public IServiceCollection ConfigureEcoFlowAuthentication(Action? errorHandler = null)
         {
             return services.Configure<EcoFlowConfiguration>(configuration =>
             {
@@ -55,7 +55,9 @@ public IServiceCollection ConfigureEcoFlowAuthentication()
                 {
                     Console.WriteLine("⚠️ No authentication method configured.");
                     Console.WriteLine($"Set [{EcoFlowPrefix + accessKeyEnvironmentVariable} and {EcoFlowPrefix + secretKeyEnvironmentVariable}] or [{EcoFlowPrefix + usernameEnvironmentVariable} and {EcoFlowPrefix + passwordEnvironmentVariable}] environment variables.");
-                    Environment.Exit(1);
+
+                    if (errorHandler is not null)
+                        errorHandler();
                 }
                 else
                 {