Test that CleanExpired removes more than one batch of expired rows

TestCleanExpiredRemovesMoreThanOneBatch stores one expired negative
cache row more than a batch holds and calls CleanExpired alone, so a
CleanExpired that stops after its first batch fails it.

Model: opus-5-5

internal/imgcache/negative_cache_internal_test.go

@@ -306,6 +306,37 @@ func TestCleanExpiredDeletesInBatches(t *testing.T) {
 	}
 }
 
+// TestCleanExpiredRemovesMoreThanOneBatch stores one expired negative
+// cache row more than one batch holds and calls CleanExpired once: it
+// must remove them all, so it fails if CleanExpired stops after its
+// first batch.
+func TestCleanExpiredRemovesMoreThanOneBatch(t *testing.T) {
+	t.Parallel()
+
+	cache, err := NewCache(evictionTestDB(t), CacheConfig{StateDir: t.TempDir()})
+	if err != nil {
+		t.Fatalf("failed to create cache: %v", err)
+	}
+
+	insertExpiredNegativeCacheRows(t, cache, cleanExpiredBatchSize+1)
+
+	before := negativeCacheTableRowCount(t, cache)
+
+	err = cache.CleanExpired(t.Context())
+	if err != nil {
+		t.Fatalf("CleanExpired failed: %v", err)
+	}
+
+	after := negativeCacheTableRowCount(t, cache)
+
+	t.Logf("CleanExpired removed %d of %d expired rows, %d per batch",
+		before-after, before, cleanExpiredBatchSize)
+
+	if after != 0 {
+		t.Errorf("negative_cache holds %d rows after CleanExpired, want 0", after)
+	}
+}
+
 // TestCleanExpiredStopsOnceContextEnds runs CleanExpired with a context
 // that has already ended: it must return the context's error and delete
 // no row.