fix: resolve bugs found in pre-release review

internal/store/store.go

@@ -1,10 +1,13 @@
 package store
 
 import (
+	"errors"
 	"fmt"
 	"path/filepath"
+	"time"
 
 	bolt "go.etcd.io/bbolt"
+	bolterrors "go.etcd.io/bbolt/errors"
 )
 
 type Store struct {
@@ -12,8 +15,11 @@ type Store struct {
 }
 
 func Open(dir string) (*Store, error) {
-	db, err := bolt.Open(filepath.Join(dir, ".tracks.db"), 0600, nil)
+	db, err := bolt.Open(filepath.Join(dir, ".tracks.db"), 0600, &bolt.Options{Timeout: 5 * time.Second})
 	if err != nil {
+		if errors.Is(err, bolterrors.ErrTimeout) {
+			return nil, fmt.Errorf("database is already in use by another process")
+		}
 		return nil, fmt.Errorf("failed to open database: %w", err)
 	}