feat(clients): add inbound filter + mobile page-size control

Filter bar gets an Inbound select next to Protocol — the dropdown is
narrowed to inbounds matching the chosen protocol (or shows everything
when no protocol is picked), with remark search inside the dropdown.
Choosing a protocol clears any inbound selection that no longer fits.

Server side, ClientPageParams gains an Inbound int and ListPaged runs a
clientMatchesInbound check after the protocol filter. The selection
persists in clientsFilterState localStorage alongside the existing
search/filter/protocol entries.

Mobile clients view also grows the AntD Pagination control that was
previously only on the desktop table, so page size / page navigation
are reachable from phones.

frontend/src/pages/clients/ClientsPage.css

@@ -145,6 +145,18 @@
   padding: 4px 4px 8px;
 }
 
+.card-pagination {
+  display: flex;
+  justify-content: center;
+  flex-wrap: wrap;
+  padding: 4px 0 8px;
+}
+
+.card-pagination .ant-pagination-options-size-changer,
+.card-pagination .ant-pagination-options-size-changer .ant-select-selector {
+  min-width: 88px !important;
+}
+
 .bulk-count {
   font-size: 12px;
   background: rgba(22, 119, 255, 0.12);