fix(scraper): fix ScrapeCatalogue selectors, zero-byte cache skip, and wire ScrapeRanking into runAsync

- ScrapeCatalogue: use li.novel-item (was div), extract href from outer <a> and title from h4.novel-title (was h3), detect next page via rel=next (was class=next)
- handleBrowse/triggerBrowseSnapshot: treat zero-byte MinIO cache entries as misses, skip storing empty SingleFile output
- runAsync: after a successful full-catalogue run, call ScrapeRanking and upsert each result into PocketBase ranking collection

scraper/internal/server/server.go

@@ -829,6 +829,36 @@ func (s *Server) runAsync(w http.ResponseWriter, cfg orchestrator.Config) {
 		o := orchestrator.New(cfg, s.novel, s.log, s.store)
 		runErr := o.Run(ctx)
 
+		// After a successful full-catalogue run, refresh the ranking list.
+		if runErr == nil && cfg.SingleBookURL == "" {
+			s.log.Info("runAsync: starting ScrapeRanking after catalogue run")
+			rankCtx, rankCancel := context.WithTimeout(context.Background(), 30*time.Minute)
+			defer rankCancel()
+			rankEntries, rankErrs := s.novel.ScrapeRanking(rankCtx, 0)
+			rank := 1
+			for meta := range rankEntries {
+				item := storage.RankingItem{
+					Rank:      rank,
+					Slug:      meta.Slug,
+					Title:     meta.Title,
+					Author:    meta.Author,
+					Cover:     meta.Cover,
+					Status:    meta.Status,
+					Genres:    meta.Genres,
+					SourceURL: meta.SourceURL,
+				}
+				if werr := s.store.WriteRankingItem(rankCtx, item); werr != nil {
+					s.log.Warn("runAsync: WriteRankingItem failed", "slug", meta.Slug, "err", werr)
+				}
+				rank++
+			}
+			if rerr := <-rankErrs; rerr != nil {
+				s.log.Warn("runAsync: ScrapeRanking finished with error", "err", rerr)
+			} else {
+				s.log.Info("runAsync: ScrapeRanking complete", "count", rank-1)
+			}
+		}
+
 		// Determine final status.
 		finalStatus := "done"
 		errMsg := ""
@@ -938,7 +968,7 @@ func (s *Server) handleBrowse(w http.ResponseWriter, r *http.Request) {
 
 	// ── Cache-first: try MinIO snapshot (new key layout) ─────────────────
 	cacheKey := s.store.BrowseHTMLKey(novelFireDomain, pageNum)
-	if html, ok, err := s.store.GetBrowsePage(ctx, cacheKey); err == nil && ok {
+	if html, ok, err := s.store.GetBrowsePage(ctx, cacheKey); err == nil && ok && len(html) > 0 {
 		novels, hasNext := parseBrowsePage(strings.NewReader(html))
 		s.log.Debug("browse: served from cache", "key", cacheKey)
 		w.Header().Set("Content-Type", "application/json")
@@ -1062,6 +1092,11 @@ func (s *Server) triggerBrowseSnapshot(cacheKey, pageURL string) {
 				"key", cacheKey, "err", readErr)
 			return
 		}
+		if len(htmlBytes) == 0 {
+			s.log.Warn("triggerBrowseSnapshot: SingleFile produced empty output, skipping cache",
+				"key", cacheKey)
+			return
+		}
 
 		// Store the HTML snapshot.
 		if putErr := s.store.SaveBrowsePage(ctx, cacheKey, string(htmlBytes)); putErr != nil {