feat(ECR-042): OpsCMS FeedSlot 薄写面

Admin POST/PUT 复用 admin.cms.write；C 端 GET /home/feed-slots；首页无 active 槽隐藏推荐区、失败回退展示；无新 migration。

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/api/internal/service/home/service.go

@@ -58,6 +58,24 @@ func (s *Service) ListPublicBanners(ctx context.Context, placement string) ([]re
 	return items, nil
 }
 
+// ListPublicFeedSlots returns active feed slots for placement.
+func (s *Service) ListPublicFeedSlots(ctx context.Context, placement string) ([]repository.FeedSlotRow, error) {
+	if placement == "" {
+		placement = "home"
+	}
+	if s.CMS == nil {
+		return []repository.FeedSlotRow{}, nil
+	}
+	items, err := s.CMS.ListActiveFeedSlots(ctx, placement)
+	if err != nil {
+		return nil, err
+	}
+	if items == nil {
+		items = []repository.FeedSlotRow{}
+	}
+	return items, nil
+}
+
 // ListAdmin returns all tools.
 func (s *Service) ListAdmin(ctx context.Context) ([]repository.HomeTool, error) {
 	return s.Repo.ListAll(ctx)