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-termio/src/wakeup.rs

@@ -5,9 +5,11 @@
 //! thread, any number of times; the waiter calls [`Wakeup::drain`] after
 //! `poll` reports the fd readable.
 
-use std::io;
-use std::os::fd::{AsFd, BorrowedFd, OwnedFd};
-use std::sync::Arc;
+use std::{
+    io,
+    os::fd::{AsFd, BorrowedFd, OwnedFd},
+    sync::Arc,
+};
 
 use rustix::event::{EventfdFlags, eventfd};
 
@@ -74,9 +76,10 @@ impl Wakeup {
 
 #[cfg(test)]
 mod tests {
-    use super::*;
     use rustix::event::{PollFd, PollFlags, poll};
 
+    use super::*;
+
     fn readable(w: &Wakeup) -> bool {
         let mut fds = [PollFd::from_borrowed_fd(w.as_fd(), PollFlags::IN)];
         poll(