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/closing-cash-report/closing-cash-report.component.html

@@ -133,8 +133,109 @@
       </table>
     }
 
-    @if (loaded && rows.length === 0) {
+    @if (loaded && rows.length === 0 && exchangeRows.length === 0) {
       <div class="pg-empty">No cash denomination data for this date.</div>
     }
   </div>
+
+  <!-- Cash Exchange section — separate from deposits/withdrawals (net monetary = ₹0) -->
+  @if (exchangeRows.length > 0) {
+    <div class="pg-card">
+      <div class="closing-exchange-head">
+        <mat-icon>swap_horiz</mat-icon>
+        <div>
+          <div class="closing-exchange-title">Cash Exchanges</div>
+          <div class="closing-exchange-sub">Denomination swaps recorded on this date (net cash impact: ₹0.00)</div>
+        </div>
+      </div>
+
+      @if (exchangeNoteRows.length > 0) {
+        <div class="pos-section-label">Notes</div>
+        <table class="pg-table">
+          <thead>
+            <tr>
+              <th>Denomination</th>
+              <th class="num col-in">Received Pcs</th>
+              <th class="num col-in">Received Amt</th>
+              <th class="num col-out">Given Pcs</th>
+              <th class="num col-out">Given Amt</th>
+              <th class="num col-net">Net Pcs</th>
+              <th class="num col-net">Net Amount</th>
+            </tr>
+          </thead>
+          <tbody>
+            @for (r of exchangeNoteRows; track r.denominationId) {
+              <tr>
+                <td>
+                  <span class="pg-chip">₹{{ r.denominationValue }}</span>
+                </td>
+                <td class="num col-in">{{ r.receivedCount }}</td>
+                <td class="num col-in">₹{{ r.receivedAmount | number: '1.2-2' }}</td>
+                <td class="num col-out">{{ r.givenCount }}</td>
+                <td class="num col-out">₹{{ r.givenAmount | number: '1.2-2' }}</td>
+                <td
+                  class="num col-net"
+                  [style.color]="r.netCount > 0 ? '#16a34a' : r.netCount < 0 ? '#dc2626' : '#94a3b8'"
+                >
+                  {{ r.netCount > 0 ? '+' : '' }}{{ r.netCount }}
+                </td>
+                <td
+                  class="num col-net"
+                  [style.color]="r.netCount > 0 ? '#16a34a' : r.netCount < 0 ? '#dc2626' : '#94a3b8'"
+                >
+                  {{ r.netCount >= 0 ? '' : '−' }}₹{{
+                    (r.netAmount < 0 ? -r.netAmount : r.netAmount) | number: '1.2-2'
+                  }}
+                </td>
+              </tr>
+            }
+          </tbody>
+        </table>
+      }
+
+      @if (exchangeCoinRows.length > 0) {
+        <div class="pos-section-label pos-section-label--coin">Coins</div>
+        <table class="pg-table">
+          <thead>
+            <tr>
+              <th>Denomination</th>
+              <th class="num col-in">Received Pcs</th>
+              <th class="num col-in">Received Amt</th>
+              <th class="num col-out">Given Pcs</th>
+              <th class="num col-out">Given Amt</th>
+              <th class="num col-net">Net Pcs</th>
+              <th class="num col-net">Net Amount</th>
+            </tr>
+          </thead>
+          <tbody>
+            @for (r of exchangeCoinRows; track r.denominationId) {
+              <tr>
+                <td>
+                  <span class="pg-chip pg-chip--coin">₹{{ r.denominationValue }}</span>
+                </td>
+                <td class="num col-in">{{ r.receivedCount }}</td>
+                <td class="num col-in">₹{{ r.receivedAmount | number: '1.2-2' }}</td>
+                <td class="num col-out">{{ r.givenCount }}</td>
+                <td class="num col-out">₹{{ r.givenAmount | number: '1.2-2' }}</td>
+                <td
+                  class="num col-net"
+                  [style.color]="r.netCount > 0 ? '#16a34a' : r.netCount < 0 ? '#dc2626' : '#94a3b8'"
+                >
+                  {{ r.netCount > 0 ? '+' : '' }}{{ r.netCount }}
+                </td>
+                <td
+                  class="num col-net"
+                  [style.color]="r.netCount > 0 ? '#16a34a' : r.netCount < 0 ? '#dc2626' : '#94a3b8'"
+                >
+                  {{ r.netCount >= 0 ? '' : '−' }}₹{{
+                    (r.netAmount < 0 ? -r.netAmount : r.netAmount) | number: '1.2-2'
+                  }}
+                </td>
+              </tr>
+            }
+          </tbody>
+        </table>
+      }
+    </div>
+  }
 </div>