style(clippy): auto-fix code style issues and unnecessary map_or allocations detected by cargo clippy

nvim-core/src/headless.rs

@@ -8,7 +8,11 @@ pub static HEADLESS_PROC: LazyLock<Arc<std::sync::Mutex<Option<tokio::process::C
     LazyLock::new(|| Arc::new(std::sync::Mutex::new(None)));
 
 pub async fn spawn_headless_nvim() -> Result<String, String> {
-    if std::process::Command::new("nvim").arg("--version").output().is_err() {
+    if std::process::Command::new("nvim")
+        .arg("--version")
+        .output()
+        .is_err()
+    {
         return Err("Error: Neovim is not installed or not in PATH. Cannot execute nvim tool. Fallback to basic terminal tools.".to_string());
     }