feat(auditlog): scaffold ScadaLink.AuditLog project + tests project (#23)

src/ScadaLink.AuditLog/ServiceCollectionExtensions.cs

@@ -0,0 +1,36 @@
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using ScadaLink.AuditLog.Configuration;
+
+namespace ScadaLink.AuditLog;
+
+/// <summary>
+/// Composition root for the Audit Log (#23) component. M1 registers
+/// <see cref="AuditLogOptions"/>; later milestones extend this method to wire
+/// up writers, telemetry actors, and the central ingest pipeline. Audit Log
+/// (#23) sits alongside Notification Outbox (#21) and Site Call Audit (#22).
+/// </summary>
+public static class ServiceCollectionExtensions
+{
+    /// <summary>Configuration section bound to <see cref="AuditLogOptions"/>.</summary>
+    public const string ConfigSectionName = "AuditLog";
+
+    /// <summary>
+    /// Binds <see cref="AuditLogOptions"/> from the
+    /// <see cref="ConfigSectionName"/> section of <paramref name="config"/>.
+    /// M2+ will register writers, telemetry actors, and the central ingest
+    /// pipeline here. <c>IAuditLogRepository</c> is registered by
+    /// <c>ScadaLink.ConfigurationDatabase.ServiceCollectionExtensions.AddConfigurationDatabase</c>,
+    /// so the caller (the Host on the central node) must also call that.
+    /// </summary>
+    public static IServiceCollection AddAuditLog(this IServiceCollection services, IConfiguration config)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+        ArgumentNullException.ThrowIfNull(config);
+
+        services.AddOptions<AuditLogOptions>()
+            .Bind(config.GetSection(ConfigSectionName));
+
+        return services;
+    }
+}