feat(cashier): denomination overdraft validation, exchange detail fix, cash exchange in reports

- Savings/Current/FD/RD withdrawal forms: card-style overdraft warning when
  requested denomination count exceeds cashier stock; submit blocked on overdraft
- Cash History detail view: show both RECEIVED and GIVEN denomination breakdowns
  for Cash Exchange (previously only RECEIVED side was displayed)
- Closing Cash Report: add Cash Exchanges section (denomination-wise received/given/net)
- Excess Transaction Report: include cash exchanges >= threshold with Type badge
  (Exchange/Txn) and ID Proof column for RBI/AML compliance
- cashier-shared.scss: etr-badge and closing-exchange-head styles
- Cash Exchange entry: overdraft warning redesigned to cx-overdraft-card BEM layout

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/cashier/cash-history/cash-history.component.ts

@@ -30,7 +30,7 @@ interface TxnRow {
   reversedBy: number | null;
   reversedAt: string | null;
   reverseReason: string | null;
-  type: 'transfer' | 'settlement' | 'inter';
+  type: 'transfer' | 'settlement' | 'inter' | 'exchange';
 }
 
 interface DenomDetail {
@@ -45,6 +45,8 @@ interface DenomDetail {
 interface DetailView {
   row: TxnRow;
   denominations: DenomDetail[];
+  receivedDenominations: DenomDetail[];
+  givenDenominations: DenomDetail[];
   morningTotal: number;
   loading: boolean;
 }
@@ -73,6 +75,7 @@ export class CashHistoryComponent implements OnInit {
   transfers: TxnRow[] = [];
   settlements: TxnRow[] = [];
   interCashier: TxnRow[] = [];
+  exchanges: TxnRow[] = [];
   loading = false;
 
   private denomKindMap = new Map<number, 'note' | 'coin'>();
@@ -98,8 +101,9 @@ export class CashHistoryComponent implements OnInit {
     forkJoin({
       transfers: this.service.getCashTransfers().pipe(catchError(() => of([]))),
       settlements: this.service.getCashSettlements().pipe(catchError(() => of([]))),
-      inter: this.service.getInterCashierTransfers().pipe(catchError(() => of([])))
-    }).subscribe(({ transfers, settlements, inter }) => {
+      inter: this.service.getInterCashierTransfers().pipe(catchError(() => of([]))),
+      exchanges: this.service.getCashExchanges().pipe(catchError(() => of([])))
+    }).subscribe(({ transfers, settlements, inter, exchanges }) => {
       this.transfers = (transfers as any[]).map((t) => ({
         id: t.id,
         date: t.transferDate,
@@ -146,12 +150,34 @@ export class CashHistoryComponent implements OnInit {
         reverseReason: i.reverseReason ?? null,
         type: 'inter'
       }));
+      this.exchanges = (exchanges as any[]).map((e) => ({
+        id: e.id,
+        date: e.exchangeDate,
+        fromParty: e.accountNo ? `Account ${e.accountNo}` : 'Walk-in Customer',
+        toParty: e.performedByUsername || '—',
+        amount: e.exchangeAmount,
+        note: e.note,
+        isReversed: e.isReversed ?? false,
+        performedByUsername: e.performedByUsername,
+        createdAt: e.createdAt,
+        reversedBy: e.reversedBy ?? null,
+        reversedAt: e.reversedAt ?? null,
+        reverseReason: e.reverseReason ?? null,
+        type: 'exchange'
+      }));
       this.loading = false;
     });
   }
 
   viewDetail(row: TxnRow): void {
-    this.detail = { row, denominations: [], morningTotal: 0, loading: true };
+    this.detail = {
+      row,
+      denominations: [],
+      receivedDenominations: [],
+      givenDenominations: [],
+      morningTotal: 0,
+      loading: true
+    };
 
     if (row.type === 'settlement' && row.fromCashierId) {
       forkJoin({
@@ -180,18 +206,27 @@ export class CashHistoryComponent implements OnInit {
     let obs$;
     if (row.type === 'transfer') obs$ = this.service.getCashTransferById(row.id);
     else if (row.type === 'settlement') obs$ = this.service.getCashSettlementById(row.id);
+    else if (row.type === 'exchange') obs$ = this.service.getCashExchange(row.id);
     else obs$ = this.service.getInterCashierById(row.id);
 
     obs$.pipe(catchError(() => of(null))).subscribe((data: any) => {
       if (this.detail) {
-        this.detail.denominations = ((data?.details || []) as any[]).map((d: any) => ({
+        const mapDenom = (d: any): DenomDetail => ({
           denominationId: d.denominationId ?? null,
           denominationValue: d.denominationValue,
           kind: this.denomKindMap.get(d.denominationId) ?? (d.denominationValue <= 5 ? 'coin' : 'note'),
           morningCount: 0,
           count: d.count,
           totalAmount: d.totalAmount
-        }));
+        });
+        if (row.type === 'exchange') {
+          const all: any[] = data?.details || [];
+          this.detail.receivedDenominations = all.filter((d: any) => d.direction === 'RECEIVED').map(mapDenom);
+          this.detail.givenDenominations = all.filter((d: any) => d.direction === 'GIVEN').map(mapDenom);
+          this.detail.denominations = this.detail.receivedDenominations;
+        } else {
+          this.detail.denominations = (data?.details || []).map(mapDenom);
+        }
         this.detail.loading = false;
       }
     });
@@ -223,6 +258,7 @@ export class CashHistoryComponent implements OnInit {
     let obs$;
     if (type === 'transfer') obs$ = this.service.reverseCashTransfer(id, reason);
     else if (type === 'settlement') obs$ = this.service.reverseCashSettlement(id, reason);
+    else if (type === 'exchange') obs$ = this.service.reverseCashExchange(id, reason);
     else obs$ = this.service.reverseInterCashierTransfer(id, reason);
 
     obs$.pipe(catchError(() => of(null))).subscribe((res: any) => {
@@ -236,7 +272,10 @@ export class CashHistoryComponent implements OnInit {
   }
 
   typeLabel(type: string): string {
-    return type === 'transfer' ? 'Cash Transfer' : type === 'settlement' ? 'Cash Settlement' : 'Inter-Cashier Transfer';
+    if (type === 'transfer') return 'Cash Transfer';
+    if (type === 'settlement') return 'Cash Settlement';
+    if (type === 'exchange') return 'Cash Exchange';
+    return 'Inter-Cashier Transfer';
   }
 
   notes(denoms: DenomDetail[]): DenomDetail[] {