fix subscription episode range dedup

internal/service/download_add_test.go

@@ -429,6 +429,64 @@ func TestAddDownloadWithMetaDoesNotDedupRangeAgainstSingleEpisodeTask(t *testing
 	}
 }
 
+func TestAddDownloadWithMetaDoesNotDedupRangeAgainstSeasonOnlyTask(t *testing.T) {
+	var addCalls int32
+	qb := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/api/v2/auth/login":
+			_, _ = w.Write([]byte("Ok."))
+		case "/api/v2/torrents/info":
+			http.Error(w, "temporary list unavailable", http.StatusInternalServerError)
+		case "/api/v2/torrents/add":
+			atomic.AddInt32(&addCalls, 1)
+			_, _ = w.Write([]byte("Ok."))
+		default:
+			http.NotFound(w, r)
+		}
+	}))
+	defer qb.Close()
+
+	db := newServiceTestDB(t, &model.DownloadTask{}, &model.DownloadClient{}, &model.Setting{})
+	repos := repository.New(db)
+	configureTestDefaultQB(t, repos, qb.URL)
+	if err := repos.Download.Create(t.Context(), &model.DownloadTask{
+		UserID:         "u1",
+		SubscriptionID: "sub-nanyang",
+		Source:         "qbittorrent",
+		URL:            "https://pt.example/download?id=old-season",
+		Title:          "Archives The Nanyang Mystery 2026 S01 2160p WEB-DL",
+		SavePath:       "/downloads/tv",
+		Status:         "completed",
+		Progress:       1,
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	svc := NewDownloadService(zap.NewNop(), repos, NewHub(zap.NewNop()), nil)
+	task, err := svc.AddDownloadWithMeta(t.Context(), "u1", "magnet:?xt=urn:btih:abababababababababababababababababababab&dn=Archives+The+Nanyang+Mystery+2026+S01E09-E10", "/downloads/tv", DownloadTaskMeta{
+		SubscriptionID: "sub-nanyang",
+		Title:          "Archives The Nanyang Mystery 2026 S01E09-E10 2160p WEB-DL",
+	})
+	if err != nil {
+		t.Fatalf("AddDownloadWithMeta returned %v, want queued because season-only task does not prove E09-E10 exists", err)
+	}
+	if task == nil {
+		t.Fatal("task = nil, want queued task")
+	}
+	if got := atomic.LoadInt32(&addCalls); got != 1 {
+		t.Fatalf("qb add calls = %d, want 1", got)
+	}
+}
+
+func TestDownloadTitleCoversRequestKeepsCompletePackDedup(t *testing.T) {
+	if !downloadTitleCoversRequest("Archives The Nanyang Mystery 2026 S01 Complete 2160p WEB-DL", "Archives The Nanyang Mystery 2026 S01E09-E10 2160p WEB-DL") {
+		t.Fatal("complete pack should cover requested episode range")
+	}
+	if downloadTitleCoversRequest("Archives The Nanyang Mystery 2026 S01 2160p WEB-DL", "Archives The Nanyang Mystery 2026 S01E09-E10 2160p WEB-DL") {
+		t.Fatal("season-only title must not cover requested episode range")
+	}
+}
+
 func TestAddDownloadWithMetaScopesSubscriptionDedupBySubscriptionOrSavePath(t *testing.T) {
 	var addCalls int32
 	qb := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {

internal/service/download_identity.go

@@ -10,6 +10,7 @@ import (
 )
 
 var torrentEpisodeToken = regexp.MustCompile(`(?i)e\d{1,3}`)
+var downloadPackTitleToken = regexp.MustCompile(`(?i)(?:^|[\s._-])(?:complete|batch|pack|合集|全集|整季|全季)(?:[\s._-]|$)`)
 
 func localAvailabilityTitleCandidates(title string) []string {
 	seen := map[string]struct{}{}
@@ -75,6 +76,9 @@ type downloadMediaIdentity struct {
 
 func parseDownloadMediaIdentity(name string) downloadMediaIdentity {
 	title, year := CleanQuery(name)
+	if isSeriesPackTitle(name) {
+		title = downloadPackTitleToken.ReplaceAllString(title, " ")
+	}
 	titleKey := normalizeAvailabilityComparable(title)
 	if titleKey == "" {
 		titleKey = normalizeAvailabilityComparable(availabilityQuery(name, ""))
@@ -101,7 +105,7 @@ func downloadTitleCoversRequest(existing, requested string) bool {
 	if current.Year > 0 && want.Year > 0 && current.Year != want.Year {
 		return false
 	}
-	if current.Pack && len(current.Episodes) == 0 {
+	if downloadIdentityCoversWholeSeason(existing, current) {
 		return true
 	}
 	if len(current.Episodes) == 0 || len(want.Episodes) == 0 {
@@ -119,6 +123,13 @@ func downloadTitleCoversRequest(existing, requested string) bool {
 	return true
 }
 
+func downloadIdentityCoversWholeSeason(title string, identity downloadMediaIdentity) bool {
+	if !identity.Pack || len(identity.Episodes) > 0 {
+		return false
+	}
+	return seriesPackRE.MatchString(title)
+}
+
 func downloadMediaIdentityKey(name string) string {
 	name = strings.ToLower(strings.TrimSpace(name))
 	if name == "" {