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-unicode/src/grapheme.rs

@@ -2,8 +2,7 @@
 //! `x.grapheme.computeGraphemeBreakNoControl` precomputed for every
 //! combination of state and break properties.
 
-use crate::props::GraphemeBreakNoControl as Gb;
-use crate::props_table::table;
+use crate::{props::GraphemeBreakNoControl as Gb, props_table::table};
 
 /// State carried between sequential [`grapheme_break`] calls
 /// (`uucode.grapheme.BreakState`).
@@ -312,9 +311,10 @@ pub fn grapheme_break_props(gb1: Gb, gb2: Gb, state: &mut BreakState) -> bool {
 
 #[cfg(test)]
 mod tests {
-    use super::*;
     use std::path::Path;
 
+    use super::*;
+
     #[test]
     fn grapheme_break_emoji_modifier() {
         // Emoji and modifier

crates/ghostty-unicode/src/lut.rs

@@ -14,8 +14,7 @@
     clippy::expect_used
 )]
 
-use std::collections::HashMap;
-use std::fmt::Write as _;
+use std::{collections::HashMap, fmt::Write as _};
 
 const BLOCK_SIZE: usize = 256;
 

crates/ghostty-unicode/src/props_table.rs

@@ -1,8 +1,10 @@
 //! The generated Unicode property lookup table for Ghostty
 //! (`props_table.zig`). Generated by `build.rs`.
 
-use crate::lut::Tables;
-use crate::props::{GraphemeBreakNoControl, Properties};
+use crate::{
+    lut::Tables,
+    props::{GraphemeBreakNoControl, Properties},
+};
 
 mod generated {
     use super::{GraphemeBreakNoControl, Properties};