Add Robot Joint Control interactive example

[luckymqz]

Summary

• Add new "Robot Joint Control" example to demonstrate direct joint position control for Franka robot
• Provides interactive UI with sliders for controlling individual joint positions
• Includes quick actions for home position and gripper open/close

Changes

• isaacsim/examples/interactive/robot_joint_control/ - New example module
  • robot_joint_control.py - Core logic extending BaseSample with joint control task
  • robot_joint_control_extension.py - UI extension with joint sliders and quick actions
  • __init__.py - Module exports
• config/extension.toml - Register new python module

Features

• 9 joint sliders (7 arm joints + 2 gripper fingers) with proper joint limits
• Home position preset button
• Gripper open/close controls
• Start/Stop physics-based joint control
• Target cube for visual reference

Test plan

• Load the example from Isaac Sim Examples Browser under "Manipulation > Robot Joint Control"
• Click "Load" to load the scene with Franka robot
• Click "Start" and verify joint sliders control the robot
• Test "Go Home" button moves robot to home position
• Test gripper open/close buttons