style: apply nightly rustfmt import grouping across the workspace

rustfmt.toml sets group_imports, imports_granularity and imports_layout,
which are nightly-only; agents formatted with stable rustfmt, which
ignored them. This is a formatting-only pass with `cargo +nightly fmt`.

Test Plan:
- cargo clippy --workspace --all-targets -- -D warnings
- cargo test --workspace

crates/ghostty-apprt-gtk/src/debug_input.rs

@@ -36,17 +36,11 @@
 //! with a few lowercase aliases (`enter`, `esc`, `up`, ...). Commands act on
 //! the active surface of the active window at the time they run.
 
-use std::cell::RefCell;
-use std::rc::Rc;
-use std::time::Duration;
+use std::{cell::RefCell, rc::Rc, time::Duration};
 
-use gtk::glib::translate::IntoGlib;
-use gtk::prelude::*;
-use gtk::{gdk, glib};
+use gtk::{gdk, glib, glib::translate::IntoGlib, prelude::*};
 
-use crate::class::application::Application;
-use crate::class::surface::Surface;
-use crate::class::window::Window;
+use crate::class::{application::Application, surface::Surface, window::Window};
 
 /// One parsed command.
 #[derive(Debug, Clone, PartialEq)]