feat(email-api): wire email-api-data; load html shell templates from DB

- Add ProjectReference to email-api-data
- Register EmailApiDbContext + run migrations on startup
- Register IEmailTemplateRepository (scoped) and IEmailTemplateService (singleton)
- SmtpEmailDispatcher: inject IEmailTemplateService; replace hardcoded
  HtmlShellStart/HtmlShellEnd string constants with DB template lookups
  (email.html-shell.start / email.html-shell.end, language "*")

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

Apis/email-api/Program.cs

@@ -1,5 +1,10 @@
 using System.Reflection;
+using EmailApi.Data;
+using EmailApi.Data.Repositories;
+using EmailApi.Data.Repositories.Contracts;
+using EmailApi.Data.Services;
 using EmailApi.Services;
+using Microsoft.EntityFrameworkCore;
 using Models.Settings;
 using Serilog;
 using StartupHelpers;
@@ -24,6 +29,19 @@ try
     builder.Services.Configure<SmtpSettings>(builder.Configuration.GetSection("Smtp"));
     builder.Services.Configure<FileStorageSettings>(builder.Configuration.GetSection("FileStorage"));
 
+    builder.Services.AddDbContext<EmailApiDbContext>(options =>
+    {
+        var connectionString = builder.Services.GetConfiguredDbConnectionString(builder.Configuration);
+        options.UseSqlServer(connectionString, sql =>
+        {
+            sql.MigrationsHistoryTable(EmailApiDbContext.MigrationTableName, EmailApiDbContext.SchemaName);
+            sql.MigrationsAssembly("email-api-data");
+        });
+    });
+
+    builder.Services.AddScoped<IEmailTemplateRepository, EfEmailTemplateRepository>();
+    builder.Services.AddSingleton<IEmailTemplateService, EmailTemplateService>();
+
     builder.Services.AddScoped<SmtpEmailDispatcher>();
 
     var app = builder.Build();
@@ -40,6 +58,13 @@ try
     app.UseAuthorization();
     app.MapControllers();
 
+    Log.Information("Running EF Core migrations if any");
+    using (var scope = app.Services.CreateScope())
+    {
+        var db = scope.ServiceProvider.GetRequiredService<EmailApiDbContext>();
+        db.Database.Migrate();
+    }
+
     Log.Information("{Service} startup complete. Listening for requests...", ServiceName);
     app.Run();
 }