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-exchange-entry/cash-exchange-entry.component.ts

@@ -45,7 +45,16 @@ export class CashExchangeEntryComponent implements OnInit {
   note = '';
   saving = false;
 
-  /** All denominations (notes then coins) — used for totals and the submit payload. */
+  // ── Customer info ──
+  isAccountHolder = false;
+  accountNo = '';
+  customerIdProof = '';
+
+  // ── Cashier position (for denomination overdraft check) ──
+  private availableMap = new Map<number, number>();
+  positionLoaded = false;
+
+  /** All denominations (notes then coins) */
   get denoms(): Denom[] {
     return [
       ...this.notes,
@@ -58,7 +67,7 @@ export class CashExchangeEntryComponent implements OnInit {
     this.exchangeDate = `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`;
     this.service.getActiveDenominations().subscribe({
       next: (list) => {
-        const rows: Denom[] = (list || []).map((x) => ({
+        const rows: Denom[] = (list || []).map((x: any) => ({
           id: x.id,
           value: x.denomination,
           kind: x.kind,
@@ -72,6 +81,18 @@ export class CashExchangeEntryComponent implements OnInit {
         this.coins = [];
       }
     });
+    this.service.getCashierPositionForMe().subscribe({
+      next: (res: any) => {
+        this.availableMap.clear();
+        ((res?.denominations || []) as any[]).forEach((d: any) => {
+          if (d.denominationId) this.availableMap.set(Number(d.denominationId), Number(d.count ?? 0));
+        });
+        this.positionLoaded = true;
+      },
+      error: () => {
+        this.positionLoaded = true;
+      }
+    });
   }
 
   countFor(side: 'r' | 'g', d: Denom): number {
@@ -107,23 +128,53 @@ export class CashExchangeEntryComponent implements OnInit {
     return this.receivedTotal > 0 && this.receivedTotal === this.givenTotal;
   }
 
+  /** Above ₹50,000 PAN/ID is mandatory per RBI guideline */
+  get needsIdProof(): boolean {
+    return this.receivedTotal >= 50000;
+  }
+
+  /** Denominations where cashier is giving more than currently available. */
+  get givenOverdraftItems(): Array<{ label: string; available: number; requested: number }> {
+    if (!this.positionLoaded) return [];
+    return this.denoms
+      .map((d) => ({ label: d.label, available: this.availableMap.get(d.id) ?? 0, requested: this.countFor('g', d) }))
+      .filter((item) => item.requested > 0 && item.requested > item.available);
+  }
+
+  get hasGivenOverdraft(): boolean {
+    return this.givenOverdraftItems.length > 0;
+  }
+
+  get valid(): boolean {
+    return this.matches && (!this.needsIdProof || this.customerIdProof.trim().length > 0) && !this.hasGivenOverdraft;
+  }
+
+  toggleAccountHolder(): void {
+    this.isAccountHolder = !this.isAccountHolder;
+    if (!this.isAccountHolder) this.accountNo = '';
+  }
+
   clear(): void {
     this.receivedCounts = {};
     this.givenCounts = {};
+    this.note = '';
+    this.accountNo = '';
+    this.customerIdProof = '';
+    this.isAccountHolder = false;
   }
 
   submit(): void {
-    if (!this.matches || this.saving) {
-      return;
-    }
+    if (!this.valid || this.saving) return;
     this.saving = true;
     const build = (side: 'r' | 'g') =>
       this.denoms
         .filter((d) => this.countFor(side, d) > 0)
         .map((d) => ({ denominationId: d.id, denominationValue: d.value, count: this.countFor(side, d) }));
-    const payload = {
+    const payload: any = {
       exchangeDate: this.exchangeDate,
       note: this.note || null,
+      customerIdProof: this.customerIdProof.trim() || null,
+      accountNo: this.isAccountHolder && this.accountNo.trim() ? this.accountNo.trim() : null,
       received: build('r'),
       given: build('g')
     };
@@ -131,7 +182,6 @@ export class CashExchangeEntryComponent implements OnInit {
       next: () => {
         this.snackBar.open('Cash exchange recorded', 'Close', { duration: 3000 });
         this.clear();
-        this.note = '';
         this.saving = false;
       },
       error: () => {