fix(server/m7-353): log retry-missing errors + tighten 404 test + cover EnrichRetryMissing

internal/coverart/enricher.go

@@ -144,7 +144,10 @@ func (e *Enricher) EnrichRetryMissing(ctx context.Context, limit int) (int, erro
 		if ctx.Err() != nil {
 			return processed, ctx.Err()
 		}
-		_ = e.EnrichAlbum(ctx, r.ID)
+		if err := e.EnrichAlbum(ctx, r.ID); err != nil {
+			e.logger.Warn("coverart: retry-missing entry failed",
+				"album_id", uuidString(r.ID), "err", err)
+		}
 		processed++
 	}
 	return processed, nil

internal/coverart/enricher_test.go

@@ -164,7 +164,9 @@ func TestEnrichAlbum_MBCAA404_RecordsNone(t *testing.T) {
 
 	f := NewFetcher(FetcherConfig{BaseURL: upstream.URL, UserAgent: "test", MinPeriod: 0, HTTPClient: upstream.Client()})
 	e := NewEnricher(pool, discardLogger(), f, true)
-	_ = e.EnrichAlbum(context.Background(), id)
+	if err := e.EnrichAlbum(context.Background(), id); err != nil {
+		t.Fatalf("enrich: %v", err)
+	}
 
 	row, err := dbq.New(pool).GetAlbumWithFirstTrackPath(context.Background(), id)
 	if err != nil {
@@ -267,3 +269,62 @@ func TestRetryAlbum_DeletesMbcaaFileAndRefetches(t *testing.T) {
 		t.Errorf("source after retry = %v, want 'mbcaa'", row.CoverArtSource)
 	}
 }
+
+func TestEnrichRetryMissing_DrainsNullAndNone(t *testing.T) {
+	pool := newPool(t)
+	// Three albums:
+	//   id1: NULL source, has sidecar → drains, becomes 'sidecar'.
+	//   id2: 'none' source, has sidecar → cleared then drained, becomes 'sidecar'.
+	//   id3: 'sidecar' source already → NOT touched.
+	id1, dir1 := seedAlbumWithTrack(t, pool, "RM1", "A", "")
+	if err := os.WriteFile(filepath.Join(dir1, "cover.jpg"), []byte("c1"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	id2, dir2 := seedAlbumWithTrack(t, pool, "RM2", "B", "")
+	if err := os.WriteFile(filepath.Join(dir2, "cover.jpg"), []byte("c2"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	none := "none"
+	if err := dbq.New(pool).SetAlbumCover(context.Background(), dbq.SetAlbumCoverParams{
+		ID: id2, Column2: "", CoverArtSource: &none,
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	id3, dir3 := seedAlbumWithTrack(t, pool, "RM3", "C", "")
+	if err := os.WriteFile(filepath.Join(dir3, "cover.jpg"), []byte("c3"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	sidecar := "sidecar"
+	preservedPath := filepath.Join(dir3, "cover.jpg")
+	if err := dbq.New(pool).SetAlbumCover(context.Background(), dbq.SetAlbumCoverParams{
+		ID: id3, Column2: preservedPath, CoverArtSource: &sidecar,
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	e := NewEnricher(pool, discardLogger(), nil, false)
+	processed, err := e.EnrichRetryMissing(context.Background(), 100)
+	if err != nil {
+		t.Fatalf("retry missing: %v", err)
+	}
+	if processed != 2 {
+		t.Errorf("processed = %d, want 2 (id1 NULL + id2 'none'; id3 already 'sidecar' not touched)", processed)
+	}
+
+	q := dbq.New(pool)
+	for _, c := range []struct {
+		id   pgtype.UUID
+		want string
+	}{
+		{id1, "sidecar"},
+		{id2, "sidecar"},
+		{id3, "sidecar"},
+	} {
+		row, _ := q.GetAlbumWithFirstTrackPath(context.Background(), c.id)
+		if row.CoverArtSource == nil || *row.CoverArtSource != c.want {
+			t.Errorf("album %v source = %v, want %q", c.id, row.CoverArtSource, c.want)
+		}
+	}
+}