Fix Overview layout: stats panel, filter panel, then tables (in that order)

Placing the filter form outside the polled div (so the poll can't wipe out
typed/selected values) put it before the stat-grid, since both used to
live inside that same polled block — stats ended up after the filter
instead of before it, as it always was.

Splits the stat-grid out into its own #overview-stats div, positioned
before the filter form; the actual poll target is now #overview-tables
(just the two tables). Since #overview-stats no longer polls directly,
/overview/fragment now also renders it as an out-of-band swap alongside
the main #overview-tables response — the same hx-swap-oob idiom already
used for the shared error banner — so the stat counts still refresh every
tick even though they're outside the polled element.

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

internal/dashboard/templates/overview.html

@@ -24,20 +24,24 @@
 <h1>Обзор</h1>
 </div>
 
-<form id="overview-filter" class="panel" onsubmit="return false">
+<div id="overview-stats">
+{{template "overview_stats" .}}
+</div>
+
+<form id="overview-filter" class="panel" onsubmit="return false" style="margin-top:16px">
 <div class="panel-body field-row">
 <div class="field" style="flex:1 1 260px">
 <label for="overview-q">Поиск по IP</label>
 <input type="search" id="overview-q" name="q" value="{{.Query}}" placeholder="203.0.113.10"
-  hx-get="/overview/fragment" hx-target="#overview-live" hx-swap="innerHTML"
+  hx-get="/overview/fragment" hx-target="#overview-tables" hx-swap="innerHTML"
   hx-include="#overview-filter" hx-trigger="input changed delay:300ms"
-  hx-sync="#overview-live:queue last">
+  hx-sync="#overview-tables:queue last">
 </div>
 <div class="field">
 <label for="overview-status">Статус</label>
 <select id="overview-status" name="status"
-  hx-get="/overview/fragment" hx-target="#overview-live" hx-swap="innerHTML"
-  hx-include="#overview-filter" hx-trigger="change" hx-sync="#overview-live:queue last">
+  hx-get="/overview/fragment" hx-target="#overview-tables" hx-swap="innerHTML"
+  hx-include="#overview-filter" hx-trigger="change" hx-sync="#overview-tables:queue last">
 <option value="">Все</option>
 <option value="pass" {{if eq .StatusFilter "pass"}}selected{{end}}>pass</option>
 <option value="partial" {{if eq .StatusFilter "partial"}}selected{{end}}>partial</option>
@@ -51,8 +55,8 @@
 не показываются.</p>
 </form>
 
-<div id="overview-live" hx-get="/overview/fragment" hx-trigger="every {{.PollSeconds}}s"
-  hx-include="#overview-filter" hx-sync="#overview-live:queue last" hx-swap="innerHTML">
-{{template "overview_fragment" .}}
+<div id="overview-tables" hx-get="/overview/fragment" hx-trigger="every {{.PollSeconds}}s"
+  hx-include="#overview-filter" hx-sync="#overview-tables:queue last" hx-swap="innerHTML">
+{{template "overview_tables" .}}
 </div>
 {{end}}