test(scanner): pin the demoted-genre contract the genre fix intended

TestAudiobookTagFallbacks still asserted the verbatim "Audiobook" genre
column, but 885d6140 demoted format words to tags-only — and that
commit's message explicitly says the pinned expectation was updated to
the demoted contract. The code change landed; the test edit it
describes never did, so the full suite has been red since 13:21 today
on a test my changes never touched.

Pin the new contract: the genre column stays empty for demoted format
words and the raw candidate ("Audiobook") lands in the tags array —
exactly the tags-only behavior the fix's message documents. Full
integration suite green after this.

cmd/server/tests/audiobook_multifile_test.go

@@ -25,6 +25,7 @@ import (
 
 	"github.com/google/uuid"
 	"github.com/jackc/pgx/v5/pgtype"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
@@ -411,7 +412,12 @@ func TestAudiobookTagFallbacks(t *testing.T) {
 	require.Len(t, item.Narrators, 1, "composer tag fills narrators (Audible convention)")
 	require.Equal(t, "Tag Narrator", item.Narrators[0])
 	require.Equal(t, "Tag Series", item.Series.String, "grouping tag fills series")
-	require.Equal(t, "Audiobook", item.Genre.String, "genre tag fills genre")
+	// 885d6140 demoted format words ("Audiobook") to tags-only: the
+	// genre column stays empty and the raw candidate lands in tags.
+	// (The commit message declares this test's update; the edit itself
+	// never landed — pinned to the demoted contract now.)
+	require.Empty(t, item.Genre.String, "demoted format words never win the genre column")
+	assert.Contains(t, item.Tags, "Audiobook", "the demoted candidate lands as a tag")
 	require.False(t, item.DatePublished.Time.IsZero(), "date tag fills publish date")
 	require.Equal(t, 2020, item.DatePublished.Time.Year())
 	// ASIN/abridged/subtitle arrive only through Audible freeform atoms,