feat(shares): close share account directly on withdrawal approval; drop separate closure-request flow

Replaces the auto-submit-closure-request behavior with an immediate
account close, in the same approval action, when a withdrawal brings
shares to zero — matching the backend's new single-step close-on-
approval flow. Removes the now-unneeded Share Closure Request feature
entirely: dedicated create/list components (Clerk Dashboard + Approval
Center), routes, nav links, and the "eligible for closure" banner on
the Share Account view.

Also adds a clear "this will close the account" notice wherever a
withdrawal would zero out the account's shares — the standalone Share
Withdrawal Request page (submit + review) and Transaction Entry's
Share Redemption Transfer confirm dialog — styled as an amber warning
callout rather than a plain info line. Trims that confirm dialog to
just the required details (dropped the redundant ECS A/C No. line and
the validation-checklist block) and compacts its overall size.

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

@@ -1924,6 +1924,15 @@
           @for (line of alertModal.lines; track $index) {
             @if ($index === 0) {
               <p class="te-alert-box__desc">{{ line }}</p>
+            } @else if (line.startsWith('⚠')) {
+              <div class="te-alert-box__callout">
+                <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round">
+                  <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>{{ line.slice(1).trim() }}</span>
+              </div>
             } @else if (line.includes(':') && $index < alertModal.lines.length - 1) {
               <div class="te-alert-box__kv">
                 <span class="te-alert-box__kv-k">{{ line.split(':')[0].trim() }}</span>