Can a non-sudo subscriber communicate with a sudo-run RouDi and publisher

Issue Title: Question about process permissions: Can a non-sudo subscriber communicate with a sudo-run RouDi and publisher?

Issue Body:

Hello iceoryx team,

I have a question regarding the recommended permission model for iceoryx processes.

Scenario:

1. I start iox-roudi using sudo.
2. I start a publisher application using sudo.
3. I then try to start a subscriber application without sudo (as a regular user).

Question:

Is this mixed-permission setup (i.e., some processes running with sudo and others without) a supported and viable way for communication?

Or is it required that all communicating processes (RouDi, publishers, and subscribers) must run with consistent permissions (e.g., all as the same non-root user, or all with sudo)?

I'd appreciate any clarification on whether this is supposed to work and what the best practice is.

Thank you!

The issue names no files, tests, or entry points. Start by tracing how iox-roudi, publishers, and subscribers handle process permissions, then document whether the described sudo and non-sudo combination is supported and what permission model users should follow.