Update Cargo files to add clap and related dependencies, restructure App
to handle configuration from CLI, and update nix module to support
config source tracking. Add new cli module and adjust main to initialize
modules at startup.
Introduce a terminal UI with a progress bar and key controls, and add
utilities for collecting and querying boolean Nix options. The toggle
function also allows flipping a boolean value in the source.
The nix module now parses `/* */` comments as categories and associates
them with subsequent options. The output format has been updated to
include the category prefix before the option path. The internal state
is maintained during traversal to ensure correct category propagation
through nested structures.
