fix(platform): normalize native paths for storage and backup validation

internal/store/backup_test.go

@@ -0,0 +1,50 @@
+package store
+
+import (
+	"context"
+	"errors"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestOpenExistingUsesNativeEscapedPathWithoutCreating(t *testing.T) {
+	root := t.TempDir()
+	path := filepath.Join(root, "数据库 # %.db")
+	original, err := Open(filepath.Join(root, "source.db"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := original.SetSetting("portable", "retained"); err != nil {
+		t.Fatal(err)
+	}
+	if err := original.Snapshot(context.Background(), path); err != nil {
+		t.Fatal(err)
+	}
+	if err := original.Close(); err != nil {
+		t.Fatal(err)
+	}
+	existing, err := OpenExisting(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	value, ok, err := existing.Setting("portable")
+	if err != nil || !ok || value != "retained" {
+		t.Fatalf("existing database path: %q, %v, %v", value, ok, err)
+	}
+	if err := existing.Close(); err != nil {
+		t.Fatal(err)
+	}
+	missingPath := filepath.Join(root, "missing.db")
+	missing, err := OpenExisting(missingPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer missing.Close()
+	if _, _, err := missing.Setting("portable"); err == nil {
+		t.Fatal("missing database accepted")
+	}
+	if _, err := os.Stat(missingPath); !errors.Is(err, os.ErrNotExist) {
+		t.Fatalf("missing database was created: %v", err)
+	}
+}