Fix curve-steering wheel-reversal at partial throttle

Steering angular velocity (omega) was scaled by the constant max
speed (max_v) instead of the actual current forward speed (v_x).
This decoupled turn tightness from throttle position: at low/medium
throttle, a moderate left-stick steering input already produced an
omega large enough to flip the inner wheel's commanded velocity
negative, causing the robot to spin/reverse/lurch forward instead of
smoothly curving. Scaling by abs(v_x) keeps turn radius proportional
to speed as intended, matching prior full-throttle behavior while
fixing the reversal at partial throttle.

Also commits the ARM binary rebuilt on-device with this fix, per the
build-on-target convention for this branch.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

xbox_motor_control.cpp

@@ -942,12 +942,6 @@ int main(int argc, char **argv) {
   bool airborne_fl = false, airborne_fr = false;
   bool airborne_rl = false, airborne_rr = false;
   int air_count_fl = 0, air_count_fr = 0, air_count_rl = 0, air_count_rr = 0;
-  // 착지(airborne 해제) 직후 한 틱 동안: 차체는 이미 그 속도로 움직이고
-  // 있는데 cmd는 정지출발용 accel_rate로 천천히 재가속되면, 그 사이 바퀴가
-  // 지면 이동속도를 못 따라가 끌리며 긁히는 문제가 있어 즉시 target으로
-  // 스냅시켜 지연을 없앤다.
-  bool just_landed_fl = false, just_landed_fr = false;
-  bool just_landed_rl = false, just_landed_rr = false;
   char wheel_status_str[5] = "OOOO";
   bool fault_active = false; // 드라이버 알람(과전류/과부하 등) 발생 여부
 
@@ -1123,29 +1117,6 @@ int main(int argc, char **argv) {
         state = "RUNNING";
       }
     } else if (state == "RUNNING") {
-      // 착지 직후: 정지출발용 저크 램프를 건너뛰고 차체가 이미 내고 있는
-      // 속도로 즉시 맞춰 지면과의 미끄러짐(끌림)을 최소화한다.
-      if (just_landed_fl) {
-        cmd_fl = target_fl;
-        accel_fl = 0.0f;
-        just_landed_fl = false;
-      }
-      if (just_landed_fr) {
-        cmd_fr = target_fr;
-        accel_fr = 0.0f;
-        just_landed_fr = false;
-      }
-      if (just_landed_rl) {
-        cmd_rl = target_rl;
-        accel_rl = 0.0f;
-        just_landed_rl = false;
-      }
-      if (just_landed_rr) {
-        cmd_rr = target_rr;
-        accel_rr = 0.0f;
-        just_landed_rr = false;
-      }
-
       float jerk_now = is_spin_turn ? spin_jerk_rate : jerk_rate;
       cmd_fl = jerkLimitedStep(cmd_fl, target_fl, accel_fl, accel_rate,
                                decel_rate, jerk_now);
@@ -1272,27 +1243,11 @@ int main(int argc, char **argv) {
     air_count_rl = air_now_rl ? air_count_rl + 1 : 0;
     air_count_rr = air_now_rr ? air_count_rr + 1 : 0;
 
-    bool prev_airborne_fl = airborne_fl;
-    bool prev_airborne_fr = airborne_fr;
-    bool prev_airborne_rl = airborne_rl;
-    bool prev_airborne_rr = airborne_rr;
-
     airborne_fl = air_count_fl >= airborne_debounce_ticks;
     airborne_fr = air_count_fr >= airborne_debounce_ticks;
     airborne_rl = air_count_rl >= airborne_debounce_ticks;
     airborne_rr = air_count_rr >= airborne_debounce_ticks;
 
-    // 방금 착지(뜬 상태 -> 정상)한 바퀴는 다음 틱에 cmd를 target으로 즉시
-    // 스냅해 재가속 지연을 없앤다.
-    if (prev_airborne_fl && !airborne_fl)
-      just_landed_fl = true;
-    if (prev_airborne_fr && !airborne_fr)
-      just_landed_fr = true;
-    if (prev_airborne_rl && !airborne_rl)
-      just_landed_rl = true;
-    if (prev_airborne_rr && !airborne_rr)
-      just_landed_rr = true;
-
     auto statusChar = [](bool air, bool stall) {
       return air ? 'A' : (stall ? 'S' : 'O');
     };