fix(ibex): wire USDT LNURL-pay msat conversion

dev/apollo-federation/supergraph.graphql

@@ -268,7 +268,7 @@ type BridgeAddExternalAccountPayload
   @join__type(graph: PUBLIC)
 {
   errors: [Error!]!
-  externalAccount: BridgeExternalAccount
+  externalAccount: BridgeExternalAccountLink
 }
 
 type BridgeCreateVirtualAccountPayload
@@ -287,6 +287,13 @@ type BridgeExternalAccount
   status: String!
 }
 
+type BridgeExternalAccountLink
+  @join__type(graph: PUBLIC)
+{
+  expiresAt: String!
+  linkUrl: String!
+}
+
 input BridgeInitiateKycInput
   @join__type(graph: PUBLIC)
 {
@@ -1092,6 +1099,22 @@ A bech32-encoded HTTPS/Onion URL that can be interacted with automatically by a
 scalar Lnurl
   @join__type(graph: PUBLIC)
 
+input LnurlPaymentSendInput
+  @join__type(graph: PUBLIC)
+{
+  """Amount to spend from the USD/USDT wallet, in USD cents."""
+  amount: FractionalCentAmount!
+
+  """LNURL-pay value to decode and pay."""
+  lnurl: Lnurl!
+
+  """Optional memo for the Lightning payment."""
+  memo: Memo
+
+  """Wallet ID with sufficient balance. Must belong to the current user."""
+  walletId: WalletId!
+}
+
 input LnUsdInvoiceCreateInput
   @join__type(graph: PUBLIC)
 {
@@ -1311,6 +1334,12 @@ type Mutation
   """
   lnUsdInvoiceCreateOnBehalfOfRecipient(input: LnUsdInvoiceCreateOnBehalfOfRecipientInput!): LnInvoicePayload!
   lnUsdInvoiceFeeProbe(input: LnUsdInvoiceFeeProbeInput!): CentAmountPayload!
+
+  """
+  Pay a LNURL-pay endpoint using a USD/USDT wallet balance.
+  The wallet amount is converted to whole-satoshi millisatoshis before calling IBEX.
+  """
+  lnurlPaymentSend(input: LnurlPaymentSendInput!): PaymentSendPayload!
   merchantMapSuggest(input: MerchantMapSuggestInput!): MerchantPayload!
   onChainAddressCreate(input: OnChainAddressCreateInput!): OnChainAddressPayload!
   onChainAddressCurrent(input: OnChainAddressCurrentInput!): OnChainAddressPayload!