fixed missing columns

backend/database/sql/schemas/audio_files.sql

@@ -2,6 +2,8 @@ CREATE TABLE IF NOT EXISTS audio_files (
   id int PRIMARY KEY,
   file_path text NOT NULL UNIQUE,
   length_milliseconds int NOT NULL,
+  file_type_id int NOT NULL,
+  recording_id int NOT NULL,
   FOREIGN KEY(file_type_id) REFERENCES file_types(id),
   FOREIGN KEY(recording_id) REFERENCES recordings(id)
 );