fix: validate positive intra-bank transfer amounts

feature/transfer-intrabank/src/commonMain/kotlin/org/mifospay/feature/transfer/intrabank/confirm/TransferConfirmViewModel.kt

@@ -213,24 +213,33 @@ internal class TransferConfirmViewModel(
         }
     }
 
-    private fun validateTransfer() = when {
-        state.amount.isBlank() -> updateValidationError(Res.string.feature_make_transfer_error_empty_amount)
+    private fun validateTransfer() {
+        if (state.amount.isBlank()) {
+            updateValidationError(Res.string.feature_make_transfer_error_empty_amount)
+            return
+        }
 
-        state.amount.toDoubleOrNull() == null -> updateValidationError(Res.string.feature_make_transfer_error_invalid_amount)
+        val transferAmount = state.amount.toDoubleOrNull()
+        if (transferAmount == null || transferAmount <= 0.0) {
+            updateValidationError(Res.string.feature_make_transfer_error_invalid_amount)
+            return
+        }
 
-        state.description.isBlank() -> updateValidationError(Res.string.feature_make_transfer_error_empty_description)
+        when {
+            state.description.isBlank() -> updateValidationError(Res.string.feature_make_transfer_error_empty_description)
 
-        state.selectedAccount == null -> updateValidationError(Res.string.feature_make_transfer_error_select_account)
+            state.selectedAccount == null -> updateValidationError(Res.string.feature_make_transfer_error_select_account)
 
-        state.selectedAccount?.accountId == state.toAccountId -> {
-            updateValidationError(Res.string.feature_make_transfer_error_same_account)
-        }
+            state.selectedAccount?.accountId == state.toAccountId -> {
+                updateValidationError(Res.string.feature_make_transfer_error_same_account)
+            }
 
-        state.amount.toDouble() > state.selectedAccountBalance -> {
-            updateValidationError(Res.string.feature_make_transfer_error_insufficient_balance)
-        }
+            transferAmount > state.selectedAccountBalance -> {
+                updateValidationError(Res.string.feature_make_transfer_error_insufficient_balance)
+            }
 
-        else -> initiateTransfer()
+            else -> initiateTransfer()
+        }
     }
 
     private fun initiateTransfer() {
@@ -341,6 +350,7 @@ internal class TransferConfirmViewModel(
     private fun updateValidationError(message: StringResource) {
         mutableStateFlow.update {
             it.copy(
+                isProcessing = false,
                 dialogState = TransferConfirmState.DialogState.Error.ValidationError(message),
             )
         }
@@ -371,7 +381,8 @@ internal data class TransferConfirmState(
     val userVerificationResult: Boolean? = null,
 ) {
     val amountIsValid: Boolean
-        get() = amount.isNotEmpty() && amount.toDoubleOrNull() != null && amount.toDouble() <= selectedAccountBalance
+        get() = amount.isNotEmpty() &&
+            amount.toDoubleOrNull()?.let { it > 0.0 && it <= selectedAccountBalance } == true
 
     val descriptionIsValid: Boolean
         get() = description.trim().isNotEmpty()

feature/transfer-intrabank/src/commonTest/kotlin/org/mifospay/feature/transfer/intrabank/confirm/TransferConfirmStateTest.kt

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2026 Mifos Initiative
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See https://github.com/openMF/mobile-wallet/blob/master/LICENSE.md
+ */
+package org.mifospay.feature.transfer.intrabank.confirm
+
+import kotlin.test.Test
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+class TransferConfirmStateTest {
+
+    @Test
+    fun amountIsValidReturnsFalseForZeroAmount() {
+        val state = TransferConfirmState(
+            amount = "0",
+            selectedAccountBalance = 100.0,
+        )
+
+        assertFalse(state.amountIsValid)
+    }
+
+    @Test
+    fun amountIsValidReturnsFalseForNegativeAmount() {
+        val state = TransferConfirmState(
+            amount = "-1",
+            selectedAccountBalance = 100.0,
+        )
+
+        assertFalse(state.amountIsValid)
+    }
+
+    @Test
+    fun amountIsValidReturnsTrueForPositiveAmountWithinBalance() {
+        val state = TransferConfirmState(
+            amount = "10.50",
+            selectedAccountBalance = 100.0,
+        )
+
+        assertTrue(state.amountIsValid)
+    }
+
+    @Test
+    fun amountIsValidReturnsFalseWhenAmountExceedsBalance() {
+        val state = TransferConfirmState(
+            amount = "101",
+            selectedAccountBalance = 100.0,
+        )
+
+        assertFalse(state.amountIsValid)
+    }
+
+    @Test
+    fun amountIsValidReturnsFalseForNonNumericAmount() {
+        val state = TransferConfirmState(
+            amount = "abc",
+            selectedAccountBalance = 100.0,
+        )
+
+        assertFalse(state.amountIsValid)
+    }
+}