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-cli/src/action.rs

@@ -104,9 +104,10 @@ where
 #[cfg(test)]
 mod tests {
     #![allow(clippy::unwrap_used)]
-    use super::*;
     use ghostty_config::cli_args::split_args;
 
+    use super::*;
+
     #[derive(Debug, Clone, Copy, PartialEq, Eq)]
     enum Plain {
         Foo,