Add show_branding column to cookie banners

Internal-only flag (defaults to true) that controls whether
"Powered by Probo" branding appears on the cookie banner.
Read directly from the live row (not the version snapshot)
since branding is cosmetic, not consent-relevant.

Signed-off-by: Émile Ré <emile@getprobo.com>

pkg/cookiebanner/service.go

@@ -132,6 +132,7 @@ type (
 		PrivacyPolicyURL  string                                         `json:"privacy_policy_url"`
 		ConsentExpiryDays int                                            `json:"consent_expiry_days"`
 		ConsentMode       string                                         `json:"consent_mode"`
+		ShowBranding      bool                                           `json:"show_branding"`
 		Categories        []coredata.CookieBannerVersionSnapshotCategory `json:"categories"`
 	}
 
@@ -412,6 +413,7 @@ func (s *Service) CreateCookieBanner(
 				PrivacyPolicyURL:  req.PrivacyPolicyURL,
 				ConsentExpiryDays: req.ConsentExpiryDays,
 				ConsentMode:       req.ConsentMode,
+				ShowBranding:      true,
 				CreatedAt:         now,
 				UpdatedAt:         now,
 			}
@@ -1561,6 +1563,7 @@ func (s *Service) GetActiveBannerConfig(
 				PrivacyPolicyURL:  snapshot.PrivacyPolicyURL,
 				ConsentExpiryDays: snapshot.ConsentExpiryDays,
 				ConsentMode:       snapshot.ConsentMode,
+				ShowBranding:      banner.ShowBranding,
 				Categories:        snapshot.Categories,
 			}
 
@@ -1574,6 +1577,27 @@ func (s *Service) GetActiveBannerConfig(
 	return config, nil
 }
 
+func (s *Service) SetShowBranding(
+	ctx context.Context,
+	bannerID gid.GID,
+	show bool,
+) error {
+	return s.pg.WithTx(
+		ctx,
+		func(ctx context.Context, tx pg.Tx) error {
+			var banner coredata.CookieBanner
+			banner.ID = bannerID
+			if err := banner.UpdateShowBranding(ctx, tx, show); err != nil {
+				if errors.Is(err, coredata.ErrResourceNotFound) {
+					return ErrBannerNotFound
+				}
+				return fmt.Errorf("cannot update show_branding: %w", err)
+			}
+			return nil
+		},
+	)
+}
+
 func (s *Service) GetVisitorConsent(
 	ctx context.Context,
 	bannerID gid.GID,