feat(falyx): add persistent prompt history, multiline input support, and new enum tests

- Added `enable_prompt_history` & `prompt_history_base_dir` to Falyx, using FileHistory to persist inputs to `~/.{program}_history`
- Added `multiline` option to UserInputAction and passed through to PromptSession
- Updated examples (`argument_examples.py`, `confirm_example.py`) to enable prompt history and add TLDR examples
- Improved CLI usage tips for clarity (`[COMMAND]` instead of `[KEY]`)
- Added `test_action_types.py` and expanded `test_main.py` for init and parser coverage
- Bumped version to 0.1.76

examples/argument_examples.py

@@ -82,6 +82,7 @@ flx = Falyx(
     program="argument_examples.py",
     hide_menu_table=True,
     show_placeholder_menu=True,
+    enable_prompt_history=True,
 )
 
 flx.add_command(