PM-5245: Prefer finance engagement splits

src/apps/work/src/lib/components/BillingAccountLineItemsModal/BillingAccountLineItemsModal.spec.tsx

@@ -432,10 +432,54 @@ describe('BillingAccountLineItemsModal', () => {
                 {
                     amount: '762.66',
                     date: '2026-06-02T13:10:48.235Z',
-                    externalId: 'assignment-5245',
+                    externalId: 'assignment-5245-finance',
+                    externalName: 'Eng BA',
+                    externalType: 'ENGAGEMENT',
+                    memberPaymentAmount: '753.42',
+                },
+            ],
+            consumedBudget: 762.66,
+            markup: 0.01226408,
+            totalBudgetRemaining: 237.34,
+        })
+
+        await waitFor(() => {
+            expect(screen.getByText('$342.00'))
+                .toBeTruthy()
+            expect(screen.getByText('$420.66'))
+                .toBeTruthy()
+        })
+        expect(screen.queryByText('$753.42'))
+            .toBeNull()
+        expect(screen.queryByText('$9.24'))
+            .toBeNull()
+        expect(mockedFetchAssignmentPaymentSplits)
+            .toHaveBeenCalledWith('assignment-5245-finance')
+    })
+
+    it('uses matching finance engagement payment splits before stale billing-account split fields', async () => {
+        mockedFetchAssignmentPaymentSplits.mockResolvedValue([
+            {
+                amount: 762.66,
+                billingAccountId: '80001063',
+                challengeFee: '420.66',
+                paymentAmount: '342.00',
+                paymentId: 'd2223b35-10fc-410e-b3f5-6d6ac482caef',
+            },
+        ])
+
+        renderModal({
+            ...baseBillingAccountDetails,
+            consumedAmounts: [
+                {
+                    amount: '762.66',
+                    challengeFee: '9.24',
+                    date: '2026-06-02T13:10:48.235Z',
+                    externalId: 'assignment-5245-stale',
                     externalName: 'Eng BA',
                     externalType: 'ENGAGEMENT',
                     memberPaymentAmount: '753.42',
+                    paymentAmount: '753.42',
                 },
             ],
             consumedBudget: 762.66,
@@ -454,7 +498,7 @@ describe('BillingAccountLineItemsModal', () => {
         expect(screen.queryByText('$9.24'))
             .toBeNull()
         expect(mockedFetchAssignmentPaymentSplits)
-            .toHaveBeenCalledWith('assignment-5245')
+            .toHaveBeenCalledWith('assignment-5245-stale')
     })
 
     it('builds engagement links from assignment-backed billing rows for copilot views', () => {

src/apps/work/src/lib/components/BillingAccountLineItemsModal/BillingAccountLineItemsModal.tsx

@@ -379,16 +379,15 @@ function getChallengeLineItemIds(items: BillingAccountLineItem[]): string[] {
  * @param items Normalized billing-account line items.
  * @returns Unique assignment ids from engagement consumed rows.
  * @remarks Locked engagement rows do not correspond to completed finance
- * payments, and rows that already carry the persisted split do not need
- * additional finance lookups.
+ * payments. Consumed rows always hydrate from finance so exact payment splits
+ * can override stale or markup-derived billing-account aliases.
  */
 function getEngagementPaymentAssignmentIds(items: BillingAccountLineItem[]): string[] {
     return Array.from(new Set(
         items
             .filter(item => (
                 item.externalType === 'ENGAGEMENT'
                 && item.status === 'consumed'
-                && (item.paymentAmount === undefined || item.challengeFee === undefined)
             ))
             .map(item => normalizeRouteId(item.externalId))
             .filter((id): id is string => !!id),
@@ -643,14 +642,14 @@ function getLineItemChallengeFeeAmount(
     billingAccountDetails: BillingAccountDetails,
     challengeDetailsById: ChallengeDetailsById | undefined,
 ): number | undefined {
-    if (item.externalType === 'ENGAGEMENT' && item.challengeFee !== undefined) {
-        return Number(item.challengeFee.toFixed(2))
-    }
-
     if (engagementPaymentSplit?.challengeFee !== undefined) {
         return engagementPaymentSplit.challengeFee
     }
 
+    if (item.externalType === 'ENGAGEMENT' && item.challengeFee !== undefined) {
+        return Number(item.challengeFee.toFixed(2))
+    }
+
     const consumedChallengeFeeAmount = getConsumedChallengeFeeAmount(item)
 
     if (consumedChallengeFeeAmount !== undefined) {
@@ -680,14 +679,14 @@ function getEngagementMemberPaymentAmount(
     billingAccountDetails: BillingAccountDetails,
     engagementPaymentSplit: EngagementPaymentSplit | undefined,
 ): number | undefined {
-    if (item.paymentAmount !== undefined) {
-        return item.paymentAmount
-    }
-
     if (engagementPaymentSplit?.paymentAmount !== undefined) {
         return engagementPaymentSplit.paymentAmount
     }
 
+    if (item.paymentAmount !== undefined) {
+        return item.paymentAmount
+    }
+
     if (item.memberPaymentAmount !== undefined) {
         return item.memberPaymentAmount
     }

src/apps/work/src/lib/utils/payment.utils.spec.ts

@@ -48,6 +48,16 @@ describe('payment.utils', () => {
             .toBe('80004466')
     })
 
+    it('prefers explicit paymentAmount over generic amount when both are present', () => {
+        const payment: AssignmentPayment = {
+            amount: 762.66,
+            paymentAmount: '342.00',
+        }
+
+        expect(getPaymentAmount(payment))
+            .toBe(342)
+    })
+
     it('falls back to the total-versus-gross delta for older payment payloads', () => {
         const payment: AssignmentPayment = {
             details: [

src/apps/work/src/lib/utils/payment.utils.ts

@@ -85,14 +85,14 @@ export function formatCurrency(value: unknown): string {
 }
 
 export function getPaymentAmount(payment: AssignmentPayment): number | undefined {
-    if (payment.amount !== undefined) {
-        return toNumber(payment.amount)
-    }
-
     if (payment.paymentAmount !== undefined) {
         return toNumber(payment.paymentAmount)
     }
 
+    if (payment.amount !== undefined) {
+        return toNumber(payment.amount)
+    }
+
     const firstDetail = getFirstPaymentDetail(payment)
 
     if (firstDetail) {