RLN doesn’t support more than one virtual channel to the same peer

[bandrivskiy]

version: rgb-lightning-node @ v0.10.0-beta.3

Problem

For the LSP, we need to open two virtual channels to the same RLN at the same time for example:

1. USDT asset channel
2. LSP_USDT asset channel
3. BTC-only channel

Right now, the node allows only one virtual channel per peer. The duplicate check does not consider the asset, so if an RGB channel is already open, opening a BTC channel to the same peer is rejected, and vice versa.

This blocks the intended LSP setup where BTC and asset virtual channels should exist side by side.

Reproduce

1. Open a virtual RGB channel to a peer — succeeds.
2. Open a virtual BTC channel to the same peer — fails immediately:

virtual channel session already exists for this peer pair

Expected result

The LSP should be able to maintain both of these channels to the same client at once:

1. a virtual RGB asset channel for N assets
2. a virtual BTC-only channel

Opening the second channel should succeed while the first is still active, rather than failing with session already exists for this peer pair.

Current behavior: the second open is rejected, so concurrent virtual BTC + asset channels to the same peer are not possible.

[txalkan]

Hey, this was intentionally left out of scope for the initial implementation, so it's more of a feature than a bug.