feat(clerk): block clerk cash deposits with UI banner and save guard

Clerk cash deposits are not permitted — notes/coins denomination is
cashier vault responsibility. Shows warning banner above footer and
disables Save button when clerk selects cash payment type on a deposit.

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

src/app/cashier/transaction-entry/transaction-entry.component.html

@@ -1355,6 +1355,19 @@
             </div>
           </div>
         } @else {
+          @if (isClerkCashDeposit) {
+            <div class="te-day-block te-day-block--warning">
+              <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5">
+                <path d="M10.29 3.86L1.82 18a2 2 0 0 0 1.71 3h16.94a2 2 0 0 0 1.71-3L13.71 3.86a2 2 0 0 0-3.42 0z" />
+                <line x1="12" y1="9" x2="12" y2="13" />
+                <line x1="12" y1="17" x2="12.01" y2="17" />
+              </svg>
+              <span>
+                <strong>CASH DEPOSIT NOT PERMITTED</strong> — Cash deposits can only be processed by the cashier.
+                Notes/coins denomination is managed at the cashier vault.
+              </span>
+            </div>
+          }
           <div class="ws-footer">
             <div class="ws-footer__stats">
               <button class="ws-btn ws-btn--ghost ws-btn--exit" type="button" (click)="onExit()">Exit</button>
@@ -1364,7 +1377,12 @@
               <button class="ws-btn ws-btn--mode" type="button">Change Tr.Mode</button>
             </div>
             <div class="ws-footer__actions">
-              <button class="ws-btn ws-btn--post" type="button" (click)="onSave()" [disabled]="saving">
+              <button
+                class="ws-btn ws-btn--post"
+                type="button"
+                (click)="onSave()"
+                [disabled]="saving || isClerkCashDeposit"
+              >
                 <svg width="13" height="13" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5">
                   <polyline points="20 6 9 17 4 12" />
                 </svg>