[bug]: `lncli lookupinvoice` shows `amt_paid_sat` when assets were sent

[ZZiigguurraatt]

Consider the following network

                       TAP
Alice <-------> Bob <-------> Charlie
         SAT           SAT

1. Charlie creates an invoice for 235400 assets and sends it to Alice. The invoice says 2389 sat.
2. Alice pays the invoice for 2389 sat
3. Charlie receives 235399 asset.
4. Charlie runs lncli lookupinvoice bc7b5132dbc28ee0192f522ad99a66268df5652ca7c72179894bad2c71b1c7b8
5. Charlie gets

{
    "memo": "",
    "r_preimage": "48de07718f7ef02f45ad32ae072963282377dbb437a50ae5094e3ae48a90dde8",
    "r_hash": "bc7b5132dbc28ee0192f522ad99a66268df5652ca7c72179894bad2c71b1c7b8",
    "value": "2389",
    "value_msat": "2389310",
    "settled": true,
    "creation_date": "1750190455",
    "settle_date": "1750190455",
    "payment_request": "lnbcrt23893100p1p59rjthpp5h3a4zvkmc28wqxf02g4dnxnxy6xl2efv5lrjz7vffwkjcud3c7uqdqqcqzzsxqyz5vqrzjqvry9fl47uswkl5203wpq9dskj04k8dd4kjg47zjmfnwyxunxnsgdaemye32c36mlqqqqqlgqqqqqqgq2qsp5jflvcec9p7j9f5cgdq6gur6w2enesg79248g92age278fe4c7emq9qxpqysgqkwf60vft36n4wv5z9heh6yy2n67ahecg2s4cv24zafvzjgxccaf3sxkqcwly48mpqfta7pnm77n57chs0geucexc2xphy9pze4jvmjqqdvrpfp",
    "description_hash": "",
    "expiry": "86400",
    "fallback_addr": "",
    "cltv_expiry": "80",
    "route_hints": [
        {
            "hop_hints": [
                {
                    "node_id": "030642a7f5f720eb7e8a7c5c1015b0b49f5b1dadada48af852da66e21b9334e086",
                    "chan_id": "17814874956233137144",
                    "fee_base_msat": 1000,
                    "fee_proportional_millionths": 1,
                    "cltv_expiry_delta": 80
                }
            ]
        }
    ],
    "private": true,
    "add_index": "8",
    "settle_index": "8",
    "amt_paid": "2389310",
    "amt_paid_sat": "2389",
    "amt_paid_msat": "2389310",
    "state": "SETTLED",
    "htlcs": [
        {
            "chan_id": "716881581375488",
            "htlc_index": "3",
            "amt_msat": "2389310",
            "accept_height": 701,
            "accept_time": "1750190455",
            "resolve_time": "1750190455",
            "expiry_height": 784,
            "state": "SETTLED",
            "custom_records": {
                "65536": "012c0020172a97a7ce2d0a5e234282cd4028530dba831efd5f7a0f2394c48e781e4d5fd601080000000000039787",
                "65538": "5617394fd5934a13eaacecfd28260ff9ec254effd85e236df73b2662ac475bf8",
                "65543": "006c016a0020172a97a7ce2d0a5e234282cd4028530dba831efd5f7a0f2394c48e781e4d5fd6014060135ceb00ac4c53a782b419cea282e58ce8e1a1b39e7761a71e44b10ccdcce44577c412b2fa36ac962ebf04b29f53e0b73a0f1f40ccbe49dca0a3ece13be480020400000083",
                "106823": "00"
            },
            "mpp_total_amt_msat": "2389310",
            "amp": null,
            "custom_channel_data": {
                "balances": [
                    {
                        "asset_id": "172a97a7ce2d0a5e234282cd4028530dba831efd5f7a0f2394c48e781e4d5fd6",
                        "amount": 235399
                    }
                ],
                "rfq_id": "5617394fd5934a13eaacecfd28260ff9ec254effd85e236df73b2662ac475bf8"
            }
        }
    ],
    "features": {
        "8": {
            "name": "tlv-onion",
            "is_required": true,
            "is_known": true
        },
        "14": {
            "name": "payment-addr",
            "is_required": true,
            "is_known": true
        },
        "17": {
            "name": "multi-path-payments",
            "is_required": false,
            "is_known": true
        },
        "25": {
            "name": "route-blinding",
            "is_required": false,
            "is_known": true
        }
    },
    "is_keysend": false,
    "payment_addr": "927ecc67050fa454d30868348e0f4e56679823c5554e82aba8cabc74e6b8f676",
    "is_amp": false,
    "amp_invoice_state": {},
    "is_blinded": false,
    "blinded_path_config": null
}

which is confusing to Charlie because his node tells him

    "amt_paid": "2389310",
    "amt_paid_sat": "2389",
    "amt_paid_msat": "2389310",

but I think these should all be 0 because he received assets and not sats.

However, I think that

    "value": "2389",
    "value_msat": "2389310",

should still be as is because they are the value of the asset and the invoice, but not necessarily an amount paid.

[Roasbeef]

The way things work from lnd's PoV, is that it always thinks it's receiving sats at all times. What we report to lnd re the amt_paid relies on our conversion from the base quote.

which is confusing to Charlie because his node tells him

These values match up, no?

        "amt_msat": "2389310",
"amt_paid": "2389310",

I would agree though that we need some APIs to enable asset specific accounting of what was sent/received.

[ZZiigguurraatt]

Also related: #1332 .

[ZZiigguurraatt]

These values match up, no?

        "amt_msat": "2389310",
"amt_paid": "2389310",

they match up, but I think that field should be 0.