refactor(feature:client): merge ViewModels, add charge validation, fix empty chargeOptions crash (#2430)

Co-authored-by: Sk Niyaj Ali <niyaj639@gmail.com>

Author: biplab1

core/model/src/commonMain/kotlin/com/mifos/core/model/objects/template/client/ChargeOptions.kt

@@ -20,15 +20,15 @@ import kotlinx.serialization.Serializable
 @Serializable
 @Parcelize
 data class ChargeOptions(
-    val id: Int,
-    val name: String,
-    val active: Boolean,
-    val penalty: Boolean,
-    val currency: Currency,
-    val amount: Double,
-    val chargeTimeType: ChargeTimeType,
-    val chargeAppliesTo: ChargeAppliesTo,
-    val chargeCalculationType: ChargeCalculationType,
-    val chargePaymentMode: ChargePaymentMode,
-    val incomeOrLiabilityAccount: IncomeOrLiabilityAccount,
+    val id: Int? = null,
+    val name: String? = null,
+    val active: Boolean? = null,
+    val penalty: Boolean? = null,
+    val currency: Currency? = null,
+    val amount: Double? = null,
+    val chargeTimeType: ChargeTimeType? = null,
+    val chargeAppliesTo: ChargeAppliesTo? = null,
+    val chargeCalculationType: ChargeCalculationType? = null,
+    val chargePaymentMode: ChargePaymentMode? = null,
+    val incomeOrLiabilityAccount: IncomeOrLiabilityAccount? = null,
 ) : Parcelable

feature/client/src/androidMain/kotlin/com/mifos/feature/client/clientCharges/ClientChargesScreen.android.kt

@@ -58,10 +58,15 @@ actual fun ClientChargeContent(
                     icon = MifosIcons.Payments,
                 )
             } else {
+                // Use a composite key of id and index to guarantee uniqueness,
+                // preventing LazyColumn crashes when duplicate ids are present in paged data.
                 LazyColumn {
                     items(
                         chargesPagingList.itemCount,
-                        key = { index -> chargesPagingList[index]?.id ?: index },
+                        key = { index ->
+                            val id = chargesPagingList[index]?.id
+                            if (id != null) "id_${id}_index_$index" else "index_$index"
+                        },
                     ) { index ->
                         chargesPagingList[index]?.let { ChargesItems(it) }
                     }

feature/client/src/commonMain/composeResources/values/strings.xml

@@ -57,6 +57,7 @@
     <string name="feature_client_charge_name">Charge Name</string>
     <string name="feature_client_charge_amount">Amount</string>
     <string name="feature_client_due_date">Due Date</string>
+    <string name="feature_client_charge_invalid_amount_format">Invalid amount format</string>
     <string name="feature_client_no_more_charges_available">No More Charges Available!</string>
     <string name="feature_client_failed_to_load_more_charges">Failed to load more Charges</string>