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/shares/shares-account-view/shares-account-view.component.scss

@@ -14,33 +14,3 @@
   min-width: 60%;
   font-weight: 400;
 }
-
-.closure-eligible-banner {
-  display: flex;
-  align-items: center;
-  gap: 10px;
-  padding: 10px 16px;
-  margin: 0 0 12px;
-  background: #eaf2ff;
-  border: 1px solid rgb(52 87 213 / 25%);
-  border-left: 3px solid #3457d5;
-  border-radius: 8px;
-  font-size: 13px;
-  color: #1b3a8a;
-
-  fa-icon {
-    color: #3457d5;
-  }
-
-  &__link {
-    margin-left: auto;
-    font-weight: 700;
-    color: #3457d5;
-    text-decoration: none;
-    white-space: nowrap;
-
-    &:hover {
-      text-decoration: underline;
-    }
-  }
-}