Feat/refactor notification infrastructure

backend/Directory.Packages.props

@@ -1,11 +1,10 @@
 <Project>
-
   <PropertyGroup>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
     <CentralPackageTransitivePinningEnabled>true</CentralPackageTransitivePinningEnabled>
   </PropertyGroup>
-
   <ItemGroup Label="Core framework &amp; Testing">
+    <PackageVersion Include="AWSSDK.S3" Version="4.0.24.3" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.13.0" />
     <PackageVersion Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="10.0.1" />
     <PackageVersion Include="Microsoft.Extensions.Hosting" Version="10.0.1" />
@@ -26,22 +25,18 @@
     <PackageVersion Include="Bogus" Version="35.6.1" />
     <PackageVersion Include="NetArchTest.Rules" Version="1.3.2" />
   </ItemGroup>
-
   <ItemGroup Label="Search &amp; Sanitization">
     <PackageVersion Include="HtmlSanitizer" Version="9.0.886" />
     <PackageVersion Include="Meilisearch" Version="0.15.5" />
   </ItemGroup>
-
   <ItemGroup Label="Email transport (SMTP)">
     <PackageVersion Include="MailKit" Version="4.8.0" />
   </ItemGroup>
-
   <ItemGroup Label="External API clients (Refit)">
     <PackageVersion Include="Refit" Version="8.0.0" />
     <PackageVersion Include="Refit.HttpClientFactory" Version="8.0.0" />
     <PackageVersion Include="Microsoft.Extensions.Http.Resilience" Version="9.4.0" />
   </ItemGroup>
-
   <ItemGroup Label="Application layer">
     <PackageVersion Include="CsvHelper" Version="33.0.1" />
     <PackageVersion Include="MediatR" Version="12.4.1" />
@@ -50,7 +45,6 @@
     <PackageVersion Include="Mapster" Version="7.4.0" />
     <PackageVersion Include="Mapster.DependencyInjection" Version="1.0.1" />
   </ItemGroup>
-
   <ItemGroup Label="Persistence (EF Core + SQL Server)">
     <PackageVersion Include="Microsoft.EntityFrameworkCore" Version="10.0.1" />
     <PackageVersion Include="Microsoft.EntityFrameworkCore.SqlServer" Version="10.0.1" />
@@ -60,12 +54,10 @@
     <PackageVersion Include="Microsoft.EntityFrameworkCore.InMemory" Version="10.0.1" />
     <PackageVersion Include="EFCore.NamingConventions" Version="10.0.0" />
   </ItemGroup>
-
   <ItemGroup Label="Redis">
     <PackageVersion Include="StackExchange.Redis" Version="2.8.31" />
     <PackageVersion Include="Microsoft.Extensions.Caching.StackExchangeRedis" Version="10.0.0" />
   </ItemGroup>
-
   <ItemGroup Label="ASP.NET Core web API">
     <PackageVersion Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="10.0.0" />
     <PackageVersion Include="Microsoft.AspNetCore.Authentication.OpenIdConnect" Version="10.0.0" />
@@ -80,14 +72,12 @@
     <!-- SignalR Redis backplane — fans out hub messages across API instances + the Worker. -->
     <PackageVersion Include="Microsoft.AspNetCore.SignalR.StackExchangeRedis" Version="10.0.0" />
   </ItemGroup>
-
   <ItemGroup Label="Identity (external users)">
     <PackageVersion Include="Microsoft.Extensions.Identity.Stores" Version="10.0.0" />
     <PackageVersion Include="Microsoft.AspNetCore.Identity" Version="2.3.1" />
     <PackageVersion Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="10.0.0" />
     <PackageVersion Include="Microsoft.AspNetCore.Identity.UI" Version="10.0.0" />
   </ItemGroup>
-
   <ItemGroup Label="Observability (Serilog + Sentry + Prometheus)">
     <PackageVersion Include="Serilog" Version="4.2.0" />
     <PackageVersion Include="Serilog.AspNetCore" Version="9.0.0" />
@@ -103,15 +93,13 @@
     <PackageVersion Include="prometheus-net.AspNetCore" Version="8.2.1" />
     <PackageVersion Include="Anthropic.SDK" Version="5.0.0" />
   </ItemGroup>
-
   <ItemGroup Label="Integration tests (Testcontainers)">
     <PackageVersion Include="Microsoft.AspNetCore.Mvc.Testing" Version="10.0.0" />
     <PackageVersion Include="Testcontainers" Version="4.4.0" />
     <PackageVersion Include="Testcontainers.MsSql" Version="4.4.0" />
     <PackageVersion Include="Testcontainers.Redis" Version="4.4.0" />
     <PackageVersion Include="WireMock.Net" Version="1.7.0" />
   </ItemGroup>
-
   <ItemGroup Label="Messaging (MassTransit)">
     <!-- MassTransit core + RabbitMQ transport. All MIT-licensed, no commercial licence required. -->
     <PackageVersion Include="MassTransit" Version="8.3.7" />
@@ -121,22 +109,18 @@
     <!-- In-memory transport used in tests and when Messaging:Transport=InMemory -->
     <PackageVersion Include="MassTransit.Testing.Helpers" Version="8.3.7" />
   </ItemGroup>
-
   <ItemGroup Label="Rate limiting (built-in 8+, no package) and problem-details helpers">
     <PackageVersion Include="Hellang.Middleware.ProblemDetails" Version="6.5.1" />
   </ItemGroup>
-
   <ItemGroup Label="Health checks">
     <PackageVersion Include="AspNetCore.HealthChecks.SqlServer" Version="9.0.0" />
     <PackageVersion Include="AspNetCore.HealthChecks.Redis" Version="9.0.0" />
   </ItemGroup>
-
   <ItemGroup Label="MediatR pipeline behaviors">
     <PackageVersion Include="Microsoft.Extensions.Logging.Abstractions" Version="10.0.1" />
     <PackageVersion Include="Microsoft.Extensions.Logging" Version="10.0.1" />
     <PackageVersion Include="Microsoft.Extensions.DependencyInjection" Version="10.0.1" />
   </ItemGroup>
-
   <ItemGroup Label="Transitive vulnerability overrides">
     <!-- Microsoft.Graph 5.80.0 pulls in Kiota 1.17.1 which has GHSA-7j59-v9qr-6fq9.
          Pin to patched version until Microsoft.Graph updates its dependency. -->
@@ -145,7 +129,6 @@
          which has GHSA-37gx-xxp4-5rgx and GHSA-w3x6-4m5h-cxqf. Pin to .NET 10 patched version. -->
     <PackageVersion Include="System.Security.Cryptography.Xml" Version="10.0.0" />
   </ItemGroup>
-
   <ItemGroup Label="Roslyn source generators (used by Domain.SourceGenerators)">
     <!-- Pin to host-compatible Roslyn. SDK 10.0.2xx ships Roslyn 4.13; referencing incompatible version raises CS9057.
          Microsoft.CodeAnalysis.Common is added explicitly because EF Core's design package
@@ -157,7 +140,6 @@
     <PackageVersion Include="Microsoft.CodeAnalysis.Analyzers" Version="3.11.0" />
     <PackageVersion Include="YamlDotNet" Version="16.3.0" />
   </ItemGroup>
-
   <ItemGroup Label="Seq + OpenTelemetry">
     <PackageVersion Include="Serilog.Sinks.Seq" Version="8.0.0" />
     <PackageVersion Include="OpenTelemetry" Version="1.11.2" />
@@ -166,5 +148,4 @@
     <PackageVersion Include="OpenTelemetry.Instrumentation.AspNetCore" Version="1.11.0" />
     <PackageVersion Include="OpenTelemetry.Instrumentation.Http" Version="1.11.0" />
   </ItemGroup>
-
-</Project>
+</Project>

backend/src/CCE.Api.External/Endpoints/Newsletter/NewsletterEndpoints.cs

@@ -0,0 +1,43 @@
+using CCE.Api.Common.Extensions;
+using CCE.Application.Content.Commands.SubscribeNewsletter;
+using MediatR;
+using Microsoft.AspNetCore.Mvc;
+
+namespace CCE.Api.External.Endpoints.Newsletter;
+
+public static class NewsletterEndpoints
+{
+    public static IEndpointRouteBuilder MapNewsletterEndpoints(this IEndpointRouteBuilder app)
+    {
+        var newsletter = app.MapGroup("/newsletter").WithTags("Newsletter");
+
+        newsletter.MapPost("/subscribe", async (
+            SubscribeNewsletterRequest req,
+            [FromHeader(Name = "Accept-Language")] string? acceptLanguage,
+            ISender sender,
+            CancellationToken ct) =>
+        {
+            var cmd = new SubscribeNewsletterCommand(req.Email, ParseLocale(acceptLanguage));
+            var result = await sender.Send(cmd, ct).ConfigureAwait(false);
+            return result.ToHttpResult();
+        })
+        .AllowAnonymous()
+        .WithName("SubscribeNewsletter");
+
+        return app;
+    }
+
+    // Extracts the primary language tag and normalises to "ar" or "en".
+    // Accept-Language can be e.g. "ar-SA,ar;q=0.9,en;q=0.8" — take the first tag only.
+    private static string ParseLocale(string? acceptLanguage)
+    {
+        if (string.IsNullOrWhiteSpace(acceptLanguage))
+            return "en";
+
+        var primary = acceptLanguage.Split(',')[0].Split(';')[0].Trim();
+        var lang = primary.Split('-')[0].ToLowerInvariant();
+        return lang == "ar" ? "ar" : "en";
+    }
+}
+
+internal sealed record SubscribeNewsletterRequest(string Email);

backend/src/CCE.Api.External/Program.cs

@@ -9,6 +9,7 @@
 using CCE.Api.Common.RateLimiting;
 using CCE.Api.Common.SignalR;
 using CCE.Api.External.Endpoints;
+using CCE.Api.External.Endpoints.Newsletter;
 using CCE.Api.External.Endpoints.Verification;
 using CCE.Api.External.Hubs;
 using CCE.Application;
@@ -126,6 +127,7 @@
 app.MapPoliciesSettingsPublicEndpoints();
 app.MapMediaPublicEndpoints();
 app.MapVerificationEndpoints();
+app.MapNewsletterEndpoints();
 app.MapStateRepresentativeEndpoints();
 app.MapCountryCodesPublicEndpoints();
 app.MapRedisAdminEndpoints();