Rename EmailApiDbContext to EmailDbContext and EmailTemplates table to Templates

Refactoring:
- Rename EmailApiDbContext class to EmailDbContext for consistency with other DbContext naming
- Rename DbSet property from EmailTemplates to Templates
- Rename table from EmailTemplates to Templates
- Update all references in Program.cs files (email-api, api, cv-search-job)
- Update all migration files and model snapshot
- Fix cv-search-job migrations assembly name: email-api-data → email-data

This improves naming consistency across the solution.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Jobs/cv-search-job/Program.cs

@@ -56,13 +56,13 @@ try
                 client.DefaultRequestHeaders.Add("X-Internal-Api-Key", key);
         });
 
-    builder.Services.AddDbContext<EmailApiDbContext>(options =>
+    builder.Services.AddDbContext<EmailDbContext>(options =>
     {
         var connectionString = builder.Services.GetConfiguredDbConnectionString(builder.Configuration);
         options.UseSqlServer(connectionString, sql =>
         {
-            sql.MigrationsHistoryTable(EmailApiDbContext.MigrationTableName, EmailApiDbContext.SchemaName);
-            sql.MigrationsAssembly("email-api-data");
+            sql.MigrationsHistoryTable(EmailDbContext.MigrationTableName, EmailDbContext.SchemaName);
+            sql.MigrationsAssembly("email-data");
         });
     });