feat: add 0xA9 feedforward frame and wire feedforward controller to motor output

- host 0xA9 frame → master_machine decode → robot_cmd publish
  via gimbal_feedforward topic → gimbal subscribe → yaw_motor.feed_input
- add DM_Feedforward_Controller_s with Kp and feed_input fields
- add feedforward term (Kp * feed_input) to motor control output
- add DM_Feedforward_Kp to motor init config

modules/motor/DMmotor/dmmotor.h

@@ -54,11 +54,17 @@ typedef struct
     float total_angle;     // multi-turn angle (degrees)
 } DM_Motor_Measure_s;
 
+typedef struct{
+    float Kp;
+    float feed_input;
+} DM_Feedforward_Controller_s;
+
 /* DM motor instance (runtime state) */
 typedef struct
 {
     DM_Motor_Measure_s measure;
     Motor_Controller_s motor_controller;
+    DM_Feedforward_Controller_s feedforward_controller;
 
     CANInstance *motor_can_instance;  // CAN communication instance
     DaemonInstance *motor_daemon;     // daemon watchdog
@@ -75,6 +81,7 @@ typedef struct
 {
     Motor_Init_Config_s motor_config;   // generic motor PID and setting config
     DM_Motor_Ctrl_Mode_e ctrl_mode;          // default control mode
+    float DM_Feedforward_Kp;
     float mit_kp;                       // MIT mode KP (only for MIT mode)
     float mit_kd;                       // MIT mode KD (only for MIT mode)
 } DM_Motor_Init_Config_s;