Let a Working Folder delete a basename.

CheckDNS needs that to Remove Domain without a second storage path.

Co-authored-by: Cursor <cursoragent@cursor.com>

files.go

@@ -32,6 +32,8 @@ type Folder interface {
 	Write(name string, data []byte) error
 	// Exists reports whether name is a non-directory file in the Working Folder.
 	Exists(name string) (bool, error)
+	// Remove deletes a basename in the Working Folder.
+	Remove(name string) error
 }
 
 // Root is User Files Root–relative folder access.
@@ -181,6 +183,18 @@ func (f localFolder) Exists(name string) (bool, error) {
 	return !info.IsDir(), nil
 }
 
+// Remove implements Folder for a local directory.
+func (f localFolder) Remove(name string) error {
+	if err := RequireBasename(name); err != nil {
+		return err
+	}
+	err := os.Remove(filepath.Join(f.dir, name))
+	if err != nil && os.IsNotExist(err) {
+		return fmt.Errorf("%w: %s", ErrNotExist, name)
+	}
+	return err
+}
+
 // RequireBasename rejects path segments that are not a single basename.
 func RequireBasename(name string) error {
 	if name == "" || name != path.Base(name) || strings.ContainsAny(name, `/\`) || strings.Contains(name, "..") {