fix: remove attitude_t, unify with INS_t

- Delete attitude_t struct from ins_task.h
- INS_Init() returns INS_t* directly instead of casting from INS.Gyro offset
- Change Gimbal_Upload_Data_s.gimbal_imu_data to INS_t* pointer
- Update gimbal.c and robot_cmd.c accordingly

application/robot_def.h

@@ -57,7 +57,7 @@ typedef struct
 /* ---- gimbal 发布给 CMD 的反馈数据 ---- */
 typedef struct
 {
-    attitude_t gimbal_imu_data;
+    INS_t *gimbal_imu_data;          // 指向 INS 实例的指针
     uint16_t yaw_motor_single_round_angle;
     uint8_t gimbal_power;
 } Gimbal_Upload_Data_s;