Add user registration emails + email infrastructure (#150)

* Add email functionality

* Add email template project and rendering service

* Update email template dir structure

* Add email header and footer components for user registration template

* update example env

* Refactor email templates namespace and components

* Format email dir

src/Core/Service/Service.Auth/Auth/RegisterService.cs

@@ -1,6 +1,9 @@
 using System.Threading.Tasks;
 using Domain.Entities;
 using Domain.Exceptions;
+using Infrastructure.Email;
+using Infrastructure.Email.Templates;
+using Infrastructure.Email.Templates.Rendering;
 using Infrastructure.PasswordHashing;
 using Infrastructure.Repository.Auth;
 
@@ -8,7 +11,9 @@ namespace Service.Auth.Auth;
 
 public class RegisterService(
     IAuthRepository authRepo,
-    IPasswordInfrastructure passwordInfrastructure
+    IPasswordInfrastructure passwordInfrastructure,
+    IEmailProvider emailProvider,
+    IEmailTemplateProvider emailTemplateProvider
 ) : IRegisterService
 {
     public async Task<UserAccount> RegisterAsync(UserAccount userAccount, string password)
@@ -23,19 +28,36 @@ public class RegisterService(
         }
 
 
-
         // password hashing
         var hashed = passwordInfrastructure.Hash(password);
 
-        // Register user with hashed password
-        return await authRepo.RegisterUserAsync(
+        // Register user with hashed password and get the created user with generated ID
+        var createdUser = await authRepo.RegisterUserAsync(
             userAccount.Username,
             userAccount.FirstName,
             userAccount.LastName,
             userAccount.Email,
             userAccount.DateOfBirth,
             hashed);
+
+
+        // Generate confirmation link (TODO: implement proper token-based confirmation)
+        var confirmationLink = $"https://thebiergarten.app/confirm?email={Uri.EscapeDataString(createdUser.Email)}";
+
+        // Render email template
+        var emailHtml = await emailTemplateProvider.RenderUserRegisteredEmailAsync(
+            createdUser.FirstName,
+            confirmationLink
+        );
+
+        // Send welcome email with rendered template
+        await emailProvider.SendAsync(
+            createdUser.Email,
+            "Welcome to The Biergarten App!",
+            emailHtml,
+            isHtml: true
+        );
+
+        return createdUser;
     }
-
-
 }

src/Core/Service/Service.Auth/Service.Auth.csproj

@@ -12,6 +12,10 @@
   <ItemGroup>
     <ProjectReference Include="..\..\Domain.Entities\Domain.Entities.csproj" />
     <ProjectReference Include="..\..\Domain.Exceptions\Domain.Exceptions.csproj" />
+    <ProjectReference
+      Include="..\..\Infrastructure\Infrastructure.Email\Infrastructure.Email.csproj" />
+    <ProjectReference
+      Include="..\..\Infrastructure\Infrastructure.Email.Templates\Infrastructure.Email.Templates.csproj" />
     <ProjectReference
       Include="..\..\Infrastructure\Infrastructure.Repository\Infrastructure.Repository.csproj" />
     <ProjectReference