fix: replace incorrect .qd with .dq in motor commands (deploy_real.py)

[dcol91863]

Summary

Fixes #61

The MotorCmd struct field for desired joint velocity is named dq, not qd. All five occurrences in deploy_real.py were using the wrong field name:

# Before (incorrect)
self.low_cmd.motor_cmd[motor_idx].qd = 0

# After (correct)
self.low_cmd.motor_cmd[motor_idx].dq = 0

Affected lines

Line	Location
125	move_to_default_pos() — leg joints interpolation loop
139	default_pos_state() — leg joints hold loop
146	default_pos_state() — arm/waist joints hold loop
209	run() — leg joints command build
217	run() — arm/waist joints command build

Impact

Using .qd silently assigns to a non-existent (or unintended) attribute on the MotorCmd object, so the desired joint velocity is never actually zeroed out during deployment. This can cause unexpected motor behavior on real hardware.

Test plan

• Verify MotorCmd field name against unitree_sdk2_python IDL definition (dq is correct)
• Deploy with corrected script and confirm motors respond as expected