diff --git a/internal/episodes/service/policy_merge_extra_test.go b/internal/episodes/service/policy_merge_extra_test.go
new file mode 100644
index 0000000..842c56d
--- /dev/null
+++ b/internal/episodes/service/policy_merge_extra_test.go
@@ -0,0 +1,116 @@
+package service
+
+import (
+	"testing"
+	"time"
+
+	"mal/integrations/jikan"
+	"mal/internal/domain"
+)
+
+func TestMergeEpisodesFiltersProviderBackedJikanToAvailableNumbers(t *testing.T) {
+	episodes := mergeEpisodes([]jikan.Episode{
+		{Episode: "1", Title: "Available"},
+		{Episode: "2", Title: "Unavailable"},
+		{Episode: "3", Title: "Dubbed"},
+	}, domain.EpisodeAvailability{
+		Sub: []int{1},
+		Dub: []int{3},
+	}, 0)
+
+	if len(episodes) != 2 {
+		t.Fatalf("len(episodes) = %d, want 2", len(episodes))
+	}
+	assertEpisode(t, episodes[0], 1, "Available", true, false, true, false)
+	assertEpisode(t, episodes[1], 3, "Dubbed", false, true, false, false)
+}
+
+func TestMergeEpisodesHonorsExpectedCountForAvailability(t *testing.T) {
+	episodes := mergeEpisodes(nil, domain.EpisodeAvailability{
+		Sub: []int{0, 1, 2, 4},
+		Dub: []int{-1, 2, 3, 5},
+	}, 3)
+
+	if len(episodes) != 3 {
+		t.Fatalf("len(episodes) = %d, want 3", len(episodes))
+	}
+	assertEpisode(t, episodes[0], 1, "Episode 1", true, false, true, false)
+	assertEpisode(t, episodes[1], 2, "Episode 2", true, true, false, false)
+	assertEpisode(t, episodes[2], 3, "Episode 3", false, true, false, false)
+}
+
+func TestIsCanonicalEpisodePayloadValidAllowsProviderPayloadWhenNoExpectedCount(t *testing.T) {
+	payload := domain.CanonicalEpisodeList{
+		Source: "AllAnime",
+		Episodes: []domain.CanonicalEpisode{
+			{Number: 1, HasSub: true},
+			{Number: 2, HasDub: true},
+		},
+	}
+
+	if !isCanonicalEpisodePayloadValid(payload, 0) {
+		t.Fatalf("expected provider-backed payload with availability to be valid")
+	}
+}
+
+func TestIsCanonicalEpisodePayloadValidRejectsOutOfRangeEpisodeNumber(t *testing.T) {
+	payload := domain.CanonicalEpisodeList{
+		Episodes: []domain.CanonicalEpisode{
+			{Number: 0, Title: "Invalid"},
+		},
+	}
+
+	if isCanonicalEpisodePayloadValid(payload, 12) {
+		t.Fatalf("expected zero episode number to be invalid")
+	}
+}
+
+func TestNextRefreshAtForFinishedAnimeIsEmpty(t *testing.T) {
+	now := time.Date(2026, 5, 16, 13, 0, 0, 0, time.UTC)
+	got := nextRefreshAt(domain.Anime{Anime: jikan.Anime{Airing: false}}, now)
+
+	if got.Valid {
+		t.Fatalf("nextRefreshAt finished anime = %s, want invalid", got.Time)
+	}
+}
+
+func TestNextRefreshAtRetriesSoonAfterRecentBroadcast(t *testing.T) {
+	anime := domain.Anime{Anime: jikan.Anime{Airing: true}}
+	anime.Broadcast.Day = "Saturdays"
+	anime.Broadcast.Time = "12:00"
+	anime.Broadcast.Timezone = "UTC"
+	now := time.Date(2026, 5, 16, 13, 0, 0, 0, time.UTC)
+
+	got := nextRefreshAt(anime, now)
+	want := now.Add(retryInterval).UTC()
+	if !got.Valid || !got.Time.Equal(want) {
+		t.Fatalf("nextRefreshAt = %#v, want %s", got, want)
+	}
+}
+
+func TestNextRefreshAtFallsBackWhenBroadcastMetadataMissing(t *testing.T) {
+	anime := domain.Anime{Anime: jikan.Anime{Airing: true}}
+	now := time.Date(2026, 5, 16, 13, 0, 0, 0, time.UTC)
+
+	got := nextRefreshAt(anime, now)
+	want := now.Add(airingFallbackRefreshInterval).UTC()
+	if !got.Valid || !got.Time.Equal(want) {
+		t.Fatalf("nextRefreshAt = %#v, want %s", got, want)
+	}
+}
+
+func TestBroadcastHelpersRejectInvalidValues(t *testing.T) {
+	if day := weekdayFromJikan("someday"); day != -1 {
+		t.Fatalf("weekdayFromJikan invalid = %d, want -1", day)
+	}
+	if _, _, ok := parseBroadcastTime("25:99"); ok {
+		t.Fatalf("parseBroadcastTime should reject invalid time")
+	}
+
+	anime := domain.Anime{Anime: jikan.Anime{MalID: 1}}
+	anime.Broadcast.Day = "Saturdays"
+	anime.Broadcast.Time = "bad"
+	if got := nextBroadcastAfter(anime, time.Date(2026, 5, 16, 13, 0, 0, 0, time.UTC)); !got.IsZero() {
+		t.Fatalf("nextBroadcastAfter invalid time = %s, want zero", got)
+	}
+}