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

sgl-router/tests/spec/chat_completion.rs

@@ -1,10 +1,12 @@
 use serde_json::json;
-use sglang_router_rs::protocols::chat::{ChatCompletionRequest, ChatMessage, UserMessageContent};
-use sglang_router_rs::protocols::common::{
-    Function, FunctionCall, FunctionChoice, StreamOptions, Tool, ToolChoice, ToolChoiceValue,
-    ToolReference,
+use sglang_router_rs::protocols::{
+    chat::{ChatCompletionRequest, ChatMessage, UserMessageContent},
+    common::{
+        Function, FunctionCall, FunctionChoice, StreamOptions, Tool, ToolChoice, ToolChoiceValue,
+        ToolReference,
+    },
+    validated::Normalizable,
 };
-use sglang_router_rs::protocols::validated::Normalizable;
 use validator::Validate;
 
 // Deprecated fields normalization tests

sgl-router/tests/spec/embedding.rs

@@ -1,6 +1,5 @@
 use serde_json::{from_str, json, to_string};
-use sglang_router_rs::protocols::common::GenerationRequest;
-use sglang_router_rs::protocols::embedding::EmbeddingRequest;
+use sglang_router_rs::protocols::{common::GenerationRequest, embedding::EmbeddingRequest};
 
 #[test]
 fn test_embedding_request_serialization_string_input() {

sgl-router/tests/spec/rerank.rs

@@ -1,9 +1,10 @@
-use serde_json::{from_str, to_string, Number, Value};
-use sglang_router_rs::protocols::common::{GenerationRequest, StringOrArray, UsageInfo};
-use sglang_router_rs::protocols::rerank::{
-    RerankRequest, RerankResponse, RerankResult, V1RerankReqInput,
-};
 use std::collections::HashMap;
+
+use serde_json::{from_str, to_string, Number, Value};
+use sglang_router_rs::protocols::{
+    common::{GenerationRequest, StringOrArray, UsageInfo},
+    rerank::{RerankRequest, RerankResponse, RerankResult, V1RerankReqInput},
+};
 use validator::Validate;
 
 #[test]