Add IP search and status filter to the Overview and Registry dashboard pages

Both pages rendered their full lists with no way to narrow them. Adds a
?q=&status= filter (substring match on address, exact match on result
status) applied dashboard-side, in Go, over the already-fetched list —
no control-api/db changes needed.

Overview: the filter form lives outside the polling target (#overview-live)
so the recurring poll never wipes out what's typed/selected; the poll and
both filter inputs share hx-sync="#overview-live:queue last" (the same
fix that resolved the earlier abandoned /ips auto-refresh races) and the
poll now carries hx-include="#overview-filter" so it keeps honoring the
current filter on every tick. Applies uniformly to both the "Текущая
проверка" and "Последние N завершённых" tables, per the confirmed design:
picking a specific status naturally hides in-progress rows, since they
have no result yet.

Registry: no polling exists there, so the filter form reuses the full page
via hx-select/hx-replace-url — simpler than adding a parallel fragment
endpoint, and gives a bookmarkable/shareable filtered URL.

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

internal/dashboard/handlers_registry.go

@@ -1,10 +1,15 @@
 package dashboard
 
-import "net/http"
+import (
+	"net/http"
+	"strings"
+)
 
 type registryPageData struct {
 	PageData
-	Items []registryItem
+	Items        []registryItem
+	Query        string
+	StatusFilter string
 }
 
 type registryDetailData struct {
@@ -15,15 +20,45 @@ type registryDetailData struct {
 // handleRegistryPage lists every address ever submitted to the check
 // queue, with a summary of its accumulated check history — the durable
 // record that survives an address being deleted from /ips and later
-// re-added. See internal/db/migrations/0007_ip_registry.sql.
+// re-added. See internal/db/migrations/0007_ip_registry.sql. Optional
+// ?q=&status= query params narrow the list by address substring and by
+// LastResult — see filterRegistryItems.
 func (s *Server) handleRegistryPage(w http.ResponseWriter, r *http.Request) {
 	items, err := s.CA.ListRegistry(r.Context())
-	data := registryPageData{Items: items}
+	q := strings.TrimSpace(r.URL.Query().Get("q"))
+	status := r.URL.Query().Get("status")
+	data := registryPageData{
+		Items:        filterRegistryItems(items, q, status),
+		Query:        q,
+		StatusFilter: status,
+	}
 	data.ActiveNav = "registry"
 	data.Banner = bannerFor(err)
 	s.renderPage(w, "registry_page", data)
 }
 
+// filterRegistryItems narrows items to those whose address contains q
+// (case-insensitive substring) and, if status is set, whose LastResult
+// matches it exactly — the registry list's search-by-IP and
+// filter-by-status, mirroring filterQueueItems in handlers_overview.go.
+func filterRegistryItems(items []registryItem, q, status string) []registryItem {
+	if q == "" && status == "" {
+		return items
+	}
+	q = strings.ToLower(q)
+	out := make([]registryItem, 0, len(items))
+	for _, it := range items {
+		if q != "" && !strings.Contains(strings.ToLower(it.IPAddress), q) {
+			continue
+		}
+		if status != "" && it.LastResult != status {
+			continue
+		}
+		out = append(out, it)
+	}
+	return out
+}
+
 // handleRegistryDetail shows one address's full retained check history
 // across every cycle it has ever run, not just the current attempt — see
 // ip_detail_content in ip_detail.html for the attempt-scoped equivalent.