feat: Add module docs, Enum coercion, tracebacks, and toggle improvements

- Add comprehensive module docstrings across the codebase for better clarity and documentation.
- Refactor Enum classes (e.g., FileType, ConfirmType) to use `_missing_` for built-in coercion from strings.
- Add `encoding` attribute to `LoadFileAction`, `SaveFileAction`, and `SelectFileAction` for more flexible file handling.
- Enable lazy file loading by default in `SelectFileAction` to improve performance.
- Simplify bottom bar toggle behavior: all toggles now use `ctrl+<key>`, eliminating the need for key conflict checks with Falyx commands.
- Add `ignore_in_history` attribute to `Command` to refine how `ExecutionRegistry` identifies the last valid result.
- Improve History command output: now includes tracebacks when displaying exceptions.

tests/test_command.py

@@ -53,7 +53,7 @@ def test_command_str():
     print(cmd)
     assert (
         str(cmd)
-        == "Command(key='TEST', description='Test Command' action='Action(name='test_action', action=dummy_action, retry=False, rollback=False)')"
+        == "Command(key='TEST', description='Test Command' action='Action(name='test_action', action=dummy_action, args=(), kwargs={}, retry=False, rollback=False)')"
     )