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-config/src/input_fields.rs

@@ -1,11 +1,15 @@
 //! `ConfigField` implementations for types owned by `ghostty-input`
 //! (the input crate cannot depend on the config crate).
 
-use crate::cli_args::{ArgError, ConfigField};
-use crate::formatter::EntryFormatter;
-use ghostty_input::{KeyRemapSet, OptionAsAlt};
 use std::fmt;
 
+use ghostty_input::{KeyRemapSet, OptionAsAlt};
+
+use crate::{
+    cli_args::{ArgError, ConfigField},
+    formatter::EntryFormatter,
+};
+
 impl ConfigField for KeyRemapSet {
     fn parse_cli(&mut self, value: Option<&str>) -> Result<(), ArgError> {
         self.parse_cli(value).map_err(|_| ArgError::InvalidValue)