feat(dashscope): 支持跨域并修改聊天接口为POST请求

- 添加了@CrossOrigin注解以支持跨域访问
- 将/chat接口从GET请求改为POST请求- 修改请求参数接收方式为@RequestBody
- 移除了不必要的导入语句

src/main/java/com/hanserwei/snailsai/controller/DashScopeController.java

@@ -3,21 +3,19 @@ package com.hanserwei.snailsai.controller;
 import jakarta.annotation.Resource;
 import org.springframework.ai.chat.client.ChatClient;
 import org.springframework.http.MediaType;
-import org.springframework.web.bind.annotation.GetMapping;
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestParam;
-import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.bind.annotation.*;
 import reactor.core.publisher.Flux;
 
 @RequestMapping("/dashscope")
 @RestController
+@CrossOrigin
 public class DashScopeController {
 
     @Resource
     private ChatClient dashScopeChatClient;
 
-    @GetMapping(value = "/chat",produces = MediaType.TEXT_EVENT_STREAM_VALUE)
-    public Flux<String> chat(@RequestParam("userPrompt") String userPrompt) {
+    @PostMapping(value = "/chat",produces = MediaType.TEXT_EVENT_STREAM_VALUE)
+    public Flux<String> chat(@RequestBody String userPrompt) {
         return dashScopeChatClient.prompt()
                 .user(userPrompt)
                 .stream()