Fix amount field input

Author: rsrsaa

Variant-Esplora/app/src/main/java/org/bitcoindevkit/devkitwallet/presentation/ui/screens/wallet/SendScreen.kt

@@ -24,6 +24,7 @@ import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.itemsIndexed
 import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.text.KeyboardOptions
 import androidx.compose.material3.AlertDialog
 import androidx.compose.material3.BottomSheetScaffold
 import androidx.compose.material3.BottomSheetScaffoldState
@@ -53,6 +54,7 @@ import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.semantics.Role
 import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.input.KeyboardType
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
@@ -351,9 +353,11 @@ private fun TransactionAmountInput(recipientList: MutableList<Recipient>, transa
                         .padding(vertical = 8.dp)
                         .weight(0.5f),
                     value = amount.value,
-                    onValueChange = {
-                        amount.value = it
-                        recipientList[index].amount = it.toULong()
+                    onValueChange = { newValue ->
+                        if (newValue.all { it.isDigit() }) {
+                            amount.value = newValue
+                            recipientList[index].amount = newValue.toULongOrNull() ?: 0.toULong()
+                        }
                     },
                     label = {
                         when (transactionType) {
@@ -372,6 +376,7 @@ private fun TransactionAmountInput(recipientList: MutableList<Recipient>, transa
                             }
                         }
                     },
+                    keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Number),
                     singleLine = true,
                     textStyle = TextStyle(color = DevkitWalletColors.white),
                     colors = OutlinedTextFieldDefaults.colors(