Add option to list tcp nodes (avahi / mDNS)

[vidplace7]

Please add an option to list nodes on the local network that are advertising over multicast DNS (avahi).

Listen for _meshtastic._tcp.

For bonus points, include the shortname and id TXT records.

See: https://github.com/meshtastic/firmware/pull/7162

[SpudGunMan]

    def add_service(self, zeroconf, type, name):
        info = zeroconf.get_service_info(type, name)
        if info:
            txt = info.properties
            print(f"Found Meshtastic node: id={txt.get(b'id', b'').decode()} shortname={txt.get(b'shortname', b'').decode()} longname={txt.get(b'longname', b'').decode()}")

[OpenSource-For-Freedom]

Got a good local unit mock test now. Current output

Discovered 1 Meshtastic service:
- MockNode (mocknode.local:4403)
  addresses: 127.0.0.1
  shortname: MOCK
  id: !welovebeef
  extra: demo

[OpenSource-For-Freedom]

• Little more granular

PS C:\Users\tbgor\Desktop\dev\python> python -m meshtastic --discover-mdns --mdns-timeout 2
Discovered 1 Meshtastic service:
- MockNode (mocknode.local:4403)
  addresses: 127.0.0.1
  shortname: LAB
  id: !123456
  hw: RAK4631
  firmware: 2.4.1
  platform: rp2040
  last_heard: 2025-10-17T16:00:00Z

[OpenSource-For-Freedom]

Extended mDNS output (main.py) to highlight hardware model, firmware version, platform/OS, and last-heard timestamps when present, while suppressing duplicate TXT fields in the general dump. Ill fork my updates in the next day or so