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

src/ScadaLink.AuditLog/Configuration/AuditLogOptions.cs

@@ -0,0 +1,10 @@
+namespace ScadaLink.AuditLog.Configuration;
+
+/// <summary>
+/// Configuration for Audit Log (#23). Bound from the "AuditLog" section of
+/// <c>appsettings.json</c>. Bundle E (M1) ships the type so the DI scaffold can
+/// register it; the full property set + validator are added by Task 9.
+/// </summary>
+public sealed class AuditLogOptions
+{
+}

src/ScadaLink.AuditLog/ScadaLink.AuditLog.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" />
+    <PackageReference Include="Microsoft.Extensions.Options" />
+    <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="../ScadaLink.Commons/ScadaLink.Commons.csproj" />
+    <!-- Audit Log (#23) sits alongside Notification Outbox (#21) and Site Call Audit (#22).
+         IAuditLogRepository is registered by ScadaLink.ConfigurationDatabase; the project
+         reference is documented here so M2 writers + telemetry actors can depend on it. -->
+    <ProjectReference Include="../ScadaLink.ConfigurationDatabase/ScadaLink.ConfigurationDatabase.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <InternalsVisibleTo Include="ScadaLink.AuditLog.Tests" />
+  </ItemGroup>
+
+</Project>

src/ScadaLink.AuditLog/ServiceCollectionExtensions.cs

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+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;
+    }
+}