[Feature request] optional mechanism in client apps to look up Node Names

[jranma]

Summary

Add an optional mechanism in client apps (Mobile / Companion / Web UI) to look up Public Keys and Node Names from an internet directory/API when a node appears as "Unknown" locally.

Is your feature request related to a problem? Please describe.

When receiving packets or messages from a node whose public key / advert hasn't been heard over the air yet, the node shows up as "Unknown" in the UI. In hybrid scenarios where users have internet access (e.g., at home, on a gateway, or cellular edge), waiting for a LoRa advertisement packet can take time or fail if the node is far away.

Proposed Solution

Introduce an optional / opt-in internet lookup feature in the client application:

1. When an unknown Node ID / Hash is encountered, the app can query an online directory or registry (e.g., map.meshcore.dev or a custom API server).
2. If the public key / node name is found in the registry, the app populates the local contacts database.
3. This feature should be disabled by default to respect privacy and maintain MeshCore's off-grid-first philosophy.

Additional Context / Alternatives Considered

• Privacy considerations: The lookup request should be optional so users operating strictly off-grid or anonymously aren't transmitting queries out to third-party servers.
• Fallbacks: The core radio protocol remains unchanged; this would be handled strictly at the companion / client level when network connectivity is available.