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/winproto/noop.rs

@@ -3,10 +3,10 @@
 
 use std::rc::Rc;
 
+use ghostty_input::Mods;
 use gtk::gdk;
 
 use super::{Result, WindowHost};
-use ghostty_input::Mods;
 
 #[derive(Debug, Default, Clone, Copy)]
 pub struct App;