feat(backend): 添加 event_logging 接口直接返回200

将原本在nginx处理的遥测日志请求移至后端，
忽略Claude Code客户端发送的日志数据。

backend/internal/server/router.go

@@ -36,6 +36,11 @@ func registerRoutes(r *gin.Engine, h *handler.Handlers, s *service.Services, rep
 		c.JSON(http.StatusOK, gin.H{"status": "ok"})
 	})
 
+	// Claude Code 遥测日志（忽略，直接返回200）
+	r.POST("/api/event_logging/batch", func(c *gin.Context) {
+		c.Status(http.StatusOK)
+	})
+
 	// Setup status endpoint (always returns needs_setup: false in normal mode)
 	// This is used by the frontend to detect when the service has restarted after setup
 	r.GET("/setup/status", func(c *gin.Context) {