refactor: drop config.toml and Viper, use DEEZER_ARL env var

internal/store/store.go

@@ -11,7 +11,7 @@ var db *bolt.DB
 
 func OpenDB(cfgDir string) error {
 	var err error
-	db, err = bolt.Open(path.Join(cfgDir, "tracks.db"), 0600, nil)
+	db, err = bolt.Open(path.Join(cfgDir, ".tracks.db"), 0600, nil)
 	if err != nil {
 		return fmt.Errorf("failed to open database: %w", err)
 	}