fix(streaming): 修正流式输出的端点URL和防缓冲header

前端：
- kieaiGeminiChatStream URL 从 /gemini/chat 改为 /gemini/chat/stream
  （后者声明了 produces=text/event-stream，nginx 不会缓冲）
- 请求 header 增加 Accept: text/event-stream

后端：
- KieAIController.geminiChatStream 补充防缓冲 header：
  X-Accel-Buffering: no + Cache-Control: no-cache
  （与 CozeController.chatStream 对齐，防止 nginx 缓冲 SSE）

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

msh_crmeb_22/crmeb-front/src/main/java/com/zbkj/front/controller/KieAIController.java

@@ -17,6 +17,7 @@ import com.zbkj.service.service.tool.ToolSora2Service;
 import io.swagger.annotations.Api;
 import io.swagger.annotations.ApiOperation;
 import io.swagger.annotations.ApiParam;
+import javax.servlet.http.HttpServletResponse;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -86,7 +87,11 @@ public class KieAIController {
      */
     @PostMapping(value = "/gemini/chat/stream", produces = "text/event-stream")
     @ApiOperation(value = "Gemini 2.5 Flash 流式对话", notes = "使用 SSE 实时推送响应")
-    public SseEmitter geminiChatStream(@RequestBody @Validated KieAIGeminiChatRequest request) {
+    public SseEmitter geminiChatStream(@RequestBody @Validated KieAIGeminiChatRequest request,
+                                       HttpServletResponse response) {
+        // 防止 nginx 缓冲 SSE 响应（与 CozeController.chatStream 对齐）
+        response.setHeader("X-Accel-Buffering", "no");
+        response.setHeader("Cache-Control", "no-cache");
         request.setStream(true);
         return toolKieAIService.geminiChatStream(request);
     }