Describe the bug
Rustecal samples publishers and subscribers do not display in ecal_mon_gui/tui.

https://github.com/eclipse-ecal/rustecal/blob/main/rustecal-core/src/core.rs#L49
it seems that c.to_ptr() is invalid.

To Reproduce
Steps to reproduce the behavior:

1. Start ecal_mon_gui
2. cargo run --bin person_send
3. cargo run --bin person_receive
4. Observe pub/sub working but not visible in ecal_mon_gui

Expected behavior
See publishers and subscribers in ecal_mon_gui

System information

• OS: Ubuntu 24.04
• Rust version: rustc 1.89.0 (29483883e 2025-08-04)
• eCAL version: 6.0.0 ppa
• rustecal version:

Additional context