style(tools, llm): 统一导入顺序与代码格式

src/prompt/composer.rs

@@ -48,7 +48,11 @@ impl PromptComposer {
 
     /// 添加一条 Tool 消息（工具执行结果回传）。
     pub fn tool(mut self, tool_call_id: impl Into<String>, content: impl Into<String>) -> Self {
-        self.push_message(Message::tool_result(tool_call_id.into(), content.into(), false));
+        self.push_message(Message::tool_result(
+            tool_call_id.into(),
+            content.into(),
+            false,
+        ));
         self
     }
 
@@ -133,11 +137,7 @@ impl PromptComposer {
     }
 
     /// 添加一条含指定 ContentBlock 的 Tool 消息。
-    pub fn tool_content(
-        mut self,
-        tool_call_id: impl Into<String>,
-        block: ContentBlock,
-    ) -> Self {
+    pub fn tool_content(mut self, tool_call_id: impl Into<String>, block: ContentBlock) -> Self {
         self.push_message(Message::ToolResult {
             tool_call_id: tool_call_id.into(),
             content: vec![block],
@@ -187,9 +187,7 @@ impl PromptComposer {
 /// 验证消息序列是否符合 LLM API 要求（Tool 消息必须紧跟含 tool_calls 的 Assistant）。
 pub fn validate_messages(messages: &[Message]) -> Result<(), PromptError> {
     if messages.is_empty() {
-        return Err(PromptError::InvalidSequence(
-            "消息列表不能为空".to_string(),
-        ));
+        return Err(PromptError::InvalidSequence("消息列表不能为空".to_string()));
     }
 
     let mut last_tool_call_ids: Vec<String> = Vec::new();
@@ -297,7 +295,8 @@ mod tests {
 
     #[test]
     fn test_template_if() {
-        let tpl = PromptTemplate::compile("Hello {{#if name}}{{name}}{{else}}Guest{{/if}}").unwrap();
+        let tpl =
+            PromptTemplate::compile("Hello {{#if name}}{{name}}{{else}}Guest{{/if}}").unwrap();
         let mut ctx = TemplateContext::new();
         ctx.insert("name", "Bob");
 
@@ -312,11 +311,14 @@ mod tests {
     fn test_template_each() {
         let tpl = PromptTemplate::compile("Items: {{#each items}}{{item}}, {{/each}}").unwrap();
         let mut ctx = TemplateContext::new();
-        ctx.insert("items", TemplateValue::Array(vec![
-            TemplateValue::String("a".to_string()),
-            TemplateValue::String("b".to_string()),
-            TemplateValue::String("c".to_string()),
-        ]));
+        ctx.insert(
+            "items",
+            TemplateValue::Array(vec![
+                TemplateValue::String("a".to_string()),
+                TemplateValue::String("b".to_string()),
+                TemplateValue::String("c".to_string()),
+            ]),
+        );
 
         let result = tpl.render(&ctx).unwrap();
         assert_eq!(result, "Items: a, b, c, ");