Clarify refund address input docs

Author: danielgranhao

lib/core/src/model.rs

@@ -502,7 +502,10 @@ pub struct PayOnchainRequest {
 pub struct PrepareRefundRequest {
     /// The address where the swap funds are locked up
     pub swap_address: String,
-    /// The address to refund the swap funds to
+    /// The Bitcoin address to refund to. To ensure a valid address is
+    /// provided, user input should be validated using
+    /// [LiquidSdk::parse](crate::sdk::LiquidSdk::parse), and `refund_address`
+    /// should be obtained from the [BitcoinAddressData] in [InputType::BitcoinAddress].
     pub refund_address: String,
     /// The fee rate in sat/vB for the refund transaction
     pub fee_rate_sat_per_vbyte: u32,
@@ -521,7 +524,10 @@ pub struct PrepareRefundResponse {
 pub struct RefundRequest {
     /// The address where the swap funds are locked up
     pub swap_address: String,
-    /// The address to refund the swap funds to
+    /// The Bitcoin address to refund to. To ensure a valid address is
+    /// provided, user input should be validated using
+    /// [LiquidSdk::parse](crate::sdk::LiquidSdk::parse), and `refund_address`
+    /// should be obtained from the [BitcoinAddressData] in [InputType::BitcoinAddress].
     pub refund_address: String,
     /// The fee rate in sat/vB for the refund transaction
     pub fee_rate_sat_per_vbyte: u32,

lib/core/src/sdk.rs

@@ -2203,7 +2203,9 @@ impl LiquidSdk {
     ///
     /// * `req` - the [PrepareRefundRequest] containing:
     ///     * `swap_address` - the swap address to refund from [RefundableSwap::swap_address]
-    ///     * `refund_address` - the Bitcoin address to refund to
+    ///     * `refund_address` - the Bitcoin address to refund to. To ensure a valid address is
+    /// provided, user input should be validated using [LiquidSdk::parse], and `refund_address`
+    /// should be obtained from the [BitcoinAddressData] in [InputType::BitcoinAddress].
     ///     * `fee_rate_sat_per_vbyte` - the fee rate at which to broadcast the refund transaction
     pub async fn prepare_refund(
         &self,
@@ -2230,7 +2232,9 @@ impl LiquidSdk {
     ///
     /// * `req` - the [RefundRequest] containing:
     ///     * `swap_address` - the swap address to refund from [RefundableSwap::swap_address]
-    ///     * `refund_address` - the Bitcoin address to refund to
+    ///     * `refund_address` - the Bitcoin address to refund to. To ensure a valid address is
+    /// provided, user input should be validated using [LiquidSdk::parse], and `refund_address`
+    /// should be obtained from the [BitcoinAddressData] in [InputType::BitcoinAddress].
     ///     * `fee_rate_sat_per_vbyte` - the fee rate at which to broadcast the refund transaction
     pub async fn refund(&self, req: &RefundRequest) -> Result<RefundResponse, PaymentError> {
         let refund_tx_id = self