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>

Apis/email-data/Repositories/EfEmailTemplateRepository.cs

@@ -6,13 +6,13 @@ namespace Email.Data.Repositories;
 
 public sealed class EfEmailTemplateRepository : IEmailTemplateRepository
 {
-    private readonly EmailApiDbContext _db;
+    private readonly EmailDbContext _db;
 
-    public EfEmailTemplateRepository(EmailApiDbContext db)
+    public EfEmailTemplateRepository(EmailDbContext db)
     {
         _db = db;
     }
 
     public async Task<IReadOnlyList<EmailTemplateEntity>> GetAllAsync(CancellationToken ct)
-        => await _db.EmailTemplates.AsNoTracking().ToListAsync(ct);
+        => await _db.Templates.AsNoTracking().ToListAsync(ct);
 }