Implemented Email and Hash Service

PostFundManagement.Domain/Extensions/EmailTelemetry.cs

@@ -0,0 +1,12 @@
+using System.Diagnostics;
+using System.Diagnostics.Metrics;
+
+namespace PostFundManagement.Domain.Extensions;
+
+public static class EmailTelemetry
+{
+    public static readonly ActivitySource Source = new("LiteCharms.EmailService");
+    public static readonly Meter Meter = new("LiteCharms.EmailService");
+    public static readonly Counter<long> EmailsSent = Meter.CreateCounter<long>("emails_sent_total", "count", "Total successful emails sent");
+    public static readonly Counter<long> EmailsFailed = Meter.CreateCounter<long>("emails_failed_total", "count", "Total failed email attempts");
+}

PostFundManagement.Domain/Extensions/Hash.cs

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+using PostFundManagement.Domain.Configuration.Hash;
+using PostFundManagement.Domain.Services;
+
+namespace PostFundManagement.Domain.Extensions;
+
+public static class Hash
+{
+    public const string HasherConfigSectionName = "HasherSettings";
+
+    public static IServiceCollection AddHashServices(this IServiceCollection services, IConfiguration configuration)
+    {
+        services.Configure<HasherSettings>(configuration.GetSection(HasherConfigSectionName));
+
+        var settings = configuration.GetSection(HasherConfigSectionName).Get<HasherSettings>();
+
+        services.AddSingleton<IHashids>(_ =>
+            new Hashids(settings!.Salt, minHashLength: settings.MinHashLength));
+
+        services.AddSingleton<HashService>();
+
+        return services;
+    }    
+}