Missing configured Channels

[arthurlutz]

When launching meshtui with my USB serial device I can see Contacts appear but not Channels. Checking those via meshcore-cli I can see them configured and working.

This might be related to #9 but in case it isn´t here is a separate issue

[ekollof]

Configured channels were only shown if MeshCore happened to have a populated channel_info_list. That attribute lives on MeshTUI's connection object, not on the library instance, so the sidebar often stayed empty even when meshcore-cli listed the same slots.

After connect we now query slots 0–7 and cache the named ones for the UI.

This is on master.