feat: make PaymentRecord immutable and add keys to HistoryScreen

app/src/main/java/com/bitcointxoko/gudariwallet/api/Models.kt

@@ -1,5 +1,6 @@
 package com.bitcointxoko.gudariwallet.api
 
+import androidx.compose.runtime.Immutable
 import com.google.gson.TypeAdapter
 import com.google.gson.annotations.JsonAdapter
 import com.google.gson.annotations.SerializedName
@@ -156,6 +157,7 @@ data class LnurlpLink(
 
 
 // ── Payment history ───────────────────────────────────────────────────────────
+@Immutable
 data class PaymentRecord(
     @SerializedName("payment_hash") val paymentHash: String,
     @SerializedName("checking_id")  val checkingId: String,
@@ -204,6 +206,8 @@ data class PaymentRecord(
     }
 }
 
+@Immutable
+
 data class PaymentExtra(
     @SerializedName("tag")            val tag: String?,
     @JsonAdapter(FlexibleStringAdapter::class)
@@ -214,6 +218,7 @@ data class PaymentExtra(
     @SerializedName("expires_at")     val expiresAt: String?
 )
 
+@Immutable
 data class SuccessAction(
     @SerializedName("tag")         val tag: String?,
     @SerializedName("message")     val message: String?,