fix(ui): polish across routing, groups, inbounds, mobile sidebar

A bundle of small UI fixes that surfaced together while reviewing the
panel.

Routing rules — stale Edit after drag:
- Dragging a rule and then clicking its Edit button used to open the
  modal with the *previous* rule's content. Root cause: desktopColumns
  was memoized with [t, isMobile, rows.length] (rows.length doesn't
  change on reorder), so the cached render function kept handing AntD
  the openEdit closure that captured the pre-drag rules array. Fix is
  a rulesRef updated each render and read inside openEdit, so even the
  cached closure sees the live array.
- Mobile rule cards on the same page were hard to tell apart: bumped
  the inter-card gap, slightly stronger border, soft shadow, and a
  small centered divider line between adjacent cards.

Mobile drawer (dark / ultra):
- The AntD Menu inside the mobile drawer was rendering with its own
  darkItemBg (#15161a / #050507) while the drawer body used the
  lighter colorBgElevated, producing visible two-tone seams. Force
  the drawer-content / drawer-body to the same dark color that the
  desktop sider uses, and make the menus transparent so they inherit.

Row menus — visual grouping:
- Groups page row menu: moved Rename above the divider so the
  ordering reads safe → divider → destructive (Remove from group,
  Delete clients, Delete group only) instead of mixing the two
  groups.
- Inbounds page row menu: inserted a divider before delAllClients /
  delete so the destructive items sit visually separated from the
  earlier safe actions.

Dropdown affordances:
- Non-danger dropdown items had no perceivable hover state (default
  colorBgTextHover is too subtle, especially under the light theme).
  Apply the same primary-tint pattern the sider/drawer menu uses: 14%
  primary background and primary color on label + icon.
- ant-dropdown-menu-item-divider now uses var(--ant-color-border)
  (and an explicit rgba in dark) so the separator is actually visible
  in the light theme.

Clients toolbar — narrow-desktop wrap:
- Between 769px and 920px, the bulk-action bar (Attach / Detach /
  Add to group / Ungroup / more + Delete) wrapped to two rows with
  Delete stranded alone on the right. In that range, switch the
  toolbar buttons to icon-only, tighten gap to 6px and inline padding
  to 8px so everything stays on one line.

frontend/src/pages/clients/ClientsPage.css

@@ -77,6 +77,19 @@
   padding: 6px 0;
 }
 
+@media (min-width: 769px) and (max-width: 920px) {
+  .card-toolbar {
+    gap: 6px;
+  }
+  .card-toolbar .ant-btn .ant-btn-icon + span,
+  .card-toolbar .ant-btn > span:not(.ant-btn-icon):not(.ant-tag):not(.anticon) {
+    display: none;
+  }
+  .card-toolbar .ant-btn {
+    padding-inline: 8px;
+  }
+}
+
 .email-cell {
   display: flex;
   flex-direction: column;