feat(19-01): add LeadsViewToggle with integrated search + list/kanban pill toggle

- LeadsViewToggle: client wrapper with useState<list|kanban>, useMemo filtered
- Search input (left) + pill toggle Lista/Kanban (right) on single row
- Filters leads by name/email/company/status/tags across both views
- Search state preserved when switching between Lista and Kanban
- LeadsSearch.tsx: replaced with re-export of LeadsViewToggle (backward compat)

src/app/admin/leads/LeadsSearch.tsx

@@ -1,46 +1,3 @@
-"use client";
-
-import { useState, useMemo } from "react";
-import { Input } from "@/components/ui/input";
-import { Search } from "lucide-react";
-import { LeadTable } from "@/components/admin/leads/LeadTable";
-import type { LeadWithTags, LeadFieldOptions } from "@/lib/admin-queries";
-
-export function LeadsSearch({
-  leads,
-  options,
-}: {
-  leads: LeadWithTags[];
-  options: LeadFieldOptions;
-}) {
-  const [query, setQuery] = useState("");
-
-  const filtered = useMemo(() => {
-    const q = query.trim().toLowerCase();
-    if (!q) return leads;
-    return leads.filter((l) => {
-      if (l.name.toLowerCase().includes(q)) return true;
-      if (l.email?.toLowerCase().includes(q)) return true;
-      if (l.company?.toLowerCase().includes(q)) return true;
-      if (l.status.toLowerCase().includes(q)) return true;
-      if (l.tags.some((t) => t.toLowerCase().includes(q))) return true;
-      return false;
-    });
-  }, [leads, query]);
-
-  return (
-    <div className="space-y-4">
-      <div className="relative max-w-sm">
-        <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-[#71717a]" />
-        <Input
-          type="text"
-          placeholder="Cerca lead..."
-          value={query}
-          onChange={(e) => setQuery(e.target.value)}
-          className="pl-9 h-9"
-        />
-      </div>
-      <LeadTable leads={filtered} options={options} />
-    </div>
-  );
-}
+// LeadsSearch is superseded by LeadsViewToggle (Phase 19).
+// Re-exported here to avoid breaking any existing import.
+export { LeadsViewToggle as LeadsSearch } from "@/components/admin/leads/LeadsViewToggle";