feat: replace SmtpEmailSender with EmailApiEmailSender in api

- EmailApiEmailSender calls email-api via IEmailApiClient Refit client
- HTML bodies built inline for contact/subscribe/file-download emails
- match and job-search emails use DB templates (rendered in caller)
- SmtpSettings moved from api-models to email-api (kept in Models.Settings namespace)
- MailKit removed from api.csproj
- SmtpEmailSender deleted; IEmailSender interface unchanged

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Apis/api/api.csproj

@@ -19,7 +19,7 @@
     <PackageReference Include="Azure.Extensions.AspNetCore.Configuration.Secrets" />
     <PackageReference Include="Azure.Identity" />
     <PackageReference Include="DotNetEnv" />
-    <PackageReference Include="MailKit" />
+    <!-- MailKit removed — email sending delegated to email-api service -->
     <PackageReference Include="Microsoft.VisualStudio.Azure.Containers.Tools.Targets" />
     <PackageReference Include="Serilog.AspNetCore" />
     <PackageReference Include="Serilog.Enrichers.Environment" />
@@ -36,6 +36,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\api-models\api-models.csproj" />
+    <ProjectReference Include="..\email-api-models\email-api-models.csproj" />
     <ProjectReference Include="..\cv-matcher-api-models\cv-matcher-api-models.csproj" />
     <ProjectReference Include="..\common\common.csproj" />
       <ProjectReference Include="..\..\Helpers\startup-helpers\startup-helpers.csproj" />