feat(enterprise-site): add WordPress support and scheduled auto-publish to sites

Add WordPress as an enterprise-site CMS type alongside pbootcms, and let
schedule tasks auto-publish generated articles to enterprise sites.

- WordPress connection/publisher service and tests; register wordpress
  media platform and relax cms_type CHECK constraint
- New publish_enterprise_site_targets JSONB column on schedule_tasks with
  array type constraint; thread targets through scheduler dispatch,
  prompt/KOL generation, and worker
- Admin UI: enterprise-site targets in generate/schedule/publish flows,
  KOL package form, MediaView, and i18n strings

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

server/internal/tenant/app/enterprise_site_pbootcms.go

@@ -66,10 +66,34 @@ type pbootCMSRequestError struct {
 	routeUnavailable bool
 }
 
+type unsupportedCMSPublisher struct {
+	cmsType string
+}
+
 func (err *pbootCMSRequestError) Error() string {
 	return err.message
 }
 
+func (p unsupportedCMSPublisher) Ping(context.Context, enterpriseSiteCredential) (*EnterpriseSiteCapability, map[string]any, error) {
+	return nil, nil, p.err()
+}
+
+func (p unsupportedCMSPublisher) Categories(context.Context, enterpriseSiteCredential) ([]EnterpriseSiteCategoryItem, []map[string]any, error) {
+	return nil, nil, p.err()
+}
+
+func (p unsupportedCMSPublisher) Publish(context.Context, enterpriseSiteCredential, cmsPublishRequest) (*cmsPublishResult, map[string]any, error) {
+	return nil, nil, p.err()
+}
+
+func (p unsupportedCMSPublisher) err() error {
+	cmsType := strings.TrimSpace(p.cmsType)
+	if cmsType == "" {
+		cmsType = "CMS"
+	}
+	return fmt.Errorf("unsupported cms type: %s", cmsType)
+}
+
 func newPBootCMSPublisher(client *http.Client) *pbootCMSPublisher {
 	if client == nil {
 		client = &http.Client{Timeout: 20 * time.Second}