Add bulk recheck and auto-refresh to the IPs dashboard page

"Перепроверить выбранные" joins the existing "Удалить выбранные" / "Очистить
всё" bulk actions, using the checked-row selection the same way delete
already does — no control-api changes needed, since forcing a recheck of a
batch of addresses (new, finished, or already-queued, skipping anything
mid-check) is exactly what POST /api/v1/admin/ips (db.SubmitIPs) already
does, and the dashboard's own SubmitIPs client method already backs both
the top add/recheck form and the single-row recheck button.

The page also now auto-refreshes every 5s (handleIPsFragment + GET
/ips/fragment), mirroring the overview page's existing hx-trigger="every
Ns" polling and reusing the same config-driven interval
(Cfg.OverviewPollIntervalS) rather than adding a duplicate knob. Since the
table now polls itself, each row's selection checkbox gets a stable id
plus hx-preserve so a checked box survives the refresh (its own DOM node
is kept) while the rest of the row still updates live.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

internal/dashboard/templates/ips.html

@@ -38,7 +38,7 @@
 </div>
 </div>
 
-<div id="ips-table-wrap">
+<div id="ips-table-wrap" hx-get="/ips/fragment" hx-trigger="every {{.PollSeconds}}s" hx-swap="innerHTML">
 {{template "ips_table" .}}
 </div>
 {{end}}
@@ -47,6 +47,7 @@
 <form id="ips-form">
 <div class="panel">
 <div class="panel-body" style="display:flex; gap:8px; align-items:center;">
+<button type="button" class="btn btn-ghost btn-sm" hx-post="/ips/recheck" hx-target="#ips-table-wrap" hx-swap="innerHTML">Перепроверить выбранные</button>
 <button type="button" class="btn btn-danger-ghost btn-sm" hx-post="/ips/delete" hx-target="#ips-table-wrap" hx-swap="innerHTML" hx-confirm="Удалить выбранные адреса без возможности восстановления?">Удалить выбранные</button>
 <button type="button" class="btn btn-danger-ghost btn-sm" hx-post="/ips/clear" hx-target="#ips-table-wrap" hx-swap="innerHTML" hx-confirm="Удалить ВСЕ адреса из очереди, включая те, что сейчас проверяются? Действие необратимо.">Очистить всё</button>
 </div>
@@ -58,7 +59,7 @@
 {{$b := ipBadge .State .OverallResult .FIPAssociatedAt $.FIPSettleSeconds}}
 {{$terminal := or (eq .State "done") (eq .State "failed") (eq .State "occupied")}}
 <tr>
-<td data-label=""><input type="checkbox" name="addresses" value="{{.IPAddress}}"></td>
+<td data-label=""><input type="checkbox" name="addresses" value="{{.IPAddress}}" id="ip-select-{{.IPAddress}}" hx-preserve="true"></td>
 <td class="addr" data-label="Адрес"><a href="/ips/{{.IPAddress}}">{{.IPAddress}}</a></td>
 <td data-label="Состояние"><span class="pill {{$b.Class}}">{{$b.Label}}</span></td>
 <td data-label="Валидатор">{{deref .OwnerValidatorID}}</td>