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

internal/fileutil/filesystem_test.go

@@ -18,7 +18,7 @@ func TestAvailableBytes(t *testing.T) {
 }
 
 func TestLocalPath(t *testing.T) {
-	for _, name := range []string{"notes/中文 note.md", "vault/.rawmark/tree-icons.json"} {
+	for _, name := range []string{"notes/中文 note.md", "vault/.rawmark/tree-icons.json", "vault/.rawmark/trash/id/meta.json"} {
 		if !IsLocalPath(name) {
 			t.Fatalf("valid path rejected: %s", name)
 		}

internal/fileutil/path.go

@@ -21,7 +21,9 @@ func IsLocalPath(name string) bool {
 			}
 		}
 		for _, part := range strings.Split(name, "/") {
-			if strings.HasSuffix(part, " ") || strings.HasSuffix(part, ".") {
+			// Reject device basenames on every supported Windows version, including extensions.
+			base, _, _ := strings.Cut(part, ".")
+			if (base != "" && !filepath.IsLocal(strings.TrimRight(base, " "))) || strings.HasSuffix(part, " ") || strings.HasSuffix(part, ".") {
 				return false
 			}
 		}

internal/fileutil/space_windows.go

@@ -1,6 +1,10 @@
 package fileutil
 
-import "golang.org/x/sys/windows"
+import (
+	"os"
+
+	"golang.org/x/sys/windows"
+)
 
 // AvailableBytes returns disk space available to the current user.
 func AvailableBytes(dir string) (uint64, error) {
@@ -10,5 +14,8 @@ func AvailableBytes(dir string) (uint64, error) {
 	}
 	var available uint64
 	err = windows.GetDiskFreeSpaceEx(name, &available, nil, nil)
-	return available, err
+	if err != nil {
+		return 0, &os.PathError{Op: "GetDiskFreeSpaceEx", Path: dir, Err: err}
+	}
+	return available, nil
 }