Add PyQt HRI display prototype packageFeature/arlab UI pyqt package

[JayH7C3]

Adds the PyQt-based HRI display prototype package for the UI part of Human-Robot Interaction.

The package implements a first ROS-integrated display prototype based on the previous UI mockup and addresses the open UI integration topics from Design Review 2. The old Tkinter demo UI is kept in legacy/, while the active prototype is implemented as a PyQt6 application.

The display can be started via ros2 run or the provided launch file and implements the following prototype pipeline:

Decision Making / Speech Output
-> publishes speech text on /tts_output
-> display subscribes to /tts_output
-> incoming messages are shown in the Speech Output card

User interaction
-> display buttons publish prototype feedback on /ui_action
-> current actions: confirm, repeat, cancel
-> this is intended as a temporary feedback path until a structured HRI feedback interface is defined

Camera display
-> display subscribes to /camera_gripper/color/image_raw
-> incoming ROS image messages are converted via cv_bridge
-> if no image topic is available, a local placeholder image is shown

The GUI provides:

• Home screen for challenge/system mode selection
• task-specific control views for Pick and Place and Laundry
• Runtime View with camera, task status, speech output, next action and progress information
• Developer View with runtime state and ROS/debug information

The current task/status/progress values are represented through an internal RuntimeState. This is used as a placeholder for the future structured HRI Output Interface from Decision Making.

Included:

• ROS 2 package arlab_ui
• executable zirbi_display
• launch file zirbi_display.launch.py
• PyQt6 GUI implementation
• camera placeholder image
• legacy Tkinter UI moved to legacy/

[TobiasNeher]

• not tested on the actual zirbi hardware
• the Legacy version was removed
• code is commented
• still a prototyp
  no further issues with the pyqt6 display implementation