Add document approval workflow

Introduce a complete approval system for document publishing. Document
versions can now require approval from selected reviewers before being
published, with automatic publishing once all approvers have approved.

- Add approval quorum and decision tables with backfill migration
- Implement request approval, approve, and reject flows with electronic
  signature support for approve decisions
- Add employee approvals page with dedicated tab and pending approvals view
- Add changelog field to publish and request approval flows
- Pre-select previous version's approvers in the publish dialog
- Show quorum approvers in document list with 100 approver hard limit
- Expose approval workflow through GraphQL, MCP, and CLI
- Remove legacy default approvers feature entirely
- Add comprehensive e2e test coverage for approval workflows

Signed-off-by: Sacha Al Himdani <sacha@getprobo.com>

pkg/esign/completion_certificate_worker.go

@@ -315,8 +315,11 @@ func (w *CompletionCertificateWorker) generateCertificate(
 	}
 	emailPresenter := emails.NewPresenterFromConfig(w.fileManager, presenterCfg, ref.UnrefOrZero(signature.SignerFullName))
 
-	docTypeName := signature.DocumentType.DisplayName()
-	subject, textBody, htmlBody, err := emailPresenter.RenderElectronicSignatureCertificate(ctx, ref.UnrefOrZero(signature.SignerFullName), docTypeName)
+	docName := ref.UnrefOrZero(signature.DocumentName)
+	if docName == "" {
+		docName = signature.DocumentType.DisplayName()
+	}
+	subject, textBody, htmlBody, err := emailPresenter.RenderElectronicSignatureCertificate(ctx, ref.UnrefOrZero(signature.SignerFullName), docName)
 	if err != nil {
 		return nil, nil, fmt.Errorf("cannot render email: %w", err)
 	}