api: refactor create flake into create clan

pkgs/clan-cli/clan_cli/arg_actions.py

@@ -0,0 +1,24 @@
+import argparse
+import logging
+from collections.abc import Sequence
+from typing import Any
+
+log = logging.getLogger(__name__)
+
+
+class AppendOptionAction(argparse.Action):
+    def __init__(self, option_strings: str, dest: str, **kwargs: Any) -> None:
+        super().__init__(option_strings, dest, **kwargs)
+
+    def __call__(
+        self,
+        parser: argparse.ArgumentParser,
+        namespace: argparse.Namespace,
+        values: str | Sequence[str] | None,
+        option_string: str | None = None,
+    ) -> None:
+        lst = getattr(namespace, self.dest)
+        lst.append("--option")
+        assert isinstance(values, list), "values must be a list"
+        lst.append(values[0])
+        lst.append(values[1])