feat(core): clone commands and actions when binding runtimes

Add clone support across Action types and Command so commands can be safely
registered or runner-bound without mutating the original instances.

- clone BaseAction implementations across simple, composite, IO, prompt, file,
  HTTP, process, and signal actions
- bind cloned commands in Falyx.add_command_from_command() and CommandRunner
- preserve local never_prompt settings when cloning actions
- rename shared runtime state from options to options_manager for consistency
- seed root and execution option namespaces consistently
- apply scoped root and namespace option overrides during routing and dispatch
- improve namespace completion by delegating option suggestions to FalyxParser
- enrich missing-value errors and error hints

tests/test_falyx/test_help.py

@@ -90,6 +90,6 @@ async def test_help_command_bad_argument(capsys):
 
     flx.add_command("U", "Untagged Command", untagged_command)
     with pytest.raises(
-        CommandArgumentError, match="Unexpected positional argument: nonexistent_tag"
+        CommandArgumentError, match="unexpected positional argument: nonexistent_tag"
     ):
         await flx.execute_command("H nonexistent_tag")