[router] Add rustfmt and set group imports by default (#11732)

sgl-router/benches/tokenizer_benchmark.rs

@@ -1,16 +1,21 @@
 //! Comprehensive tokenizer benchmark with clean summary output
 //! Each test adds a row to the final summary table
 
+use std::{
+    collections::BTreeMap,
+    path::PathBuf,
+    sync::{
+        atomic::{AtomicBool, AtomicU64, Ordering},
+        Arc, Mutex, OnceLock,
+    },
+    thread,
+    time::{Duration, Instant},
+};
+
 use criterion::{black_box, criterion_group, BenchmarkId, Criterion, Throughput};
 use sglang_router_rs::tokenizer::{
     huggingface::HuggingFaceTokenizer, sequence::Sequence, stop::*, stream::DecodeStream, traits::*,
 };
-use std::collections::BTreeMap;
-use std::path::PathBuf;
-use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
-use std::sync::{Arc, Mutex, OnceLock};
-use std::thread;
-use std::time::{Duration, Instant};
 
 // Include the common test utilities
 #[path = "../tests/common/mod.rs"]