feat(12-04): build OfferListClient with category filter, archive toggle, card grid

- Category filter chips ("Tutti" + dynamic categoryOptions), active/inactive
  styling per UI-SPEC (#1A463C / #e5e7eb)
- "Mostra offerte archiviate" toggle (default off), filters via useMemo
- Responsive card grid (1/2/3 cols) linking to /admin/offers/[id]/edit,
  with category badge and "Archiviata" indicator
- "+ Nuova Offerta" inline form calling createOfferMacro via useTransition
  + router.refresh()
- Empty state with "Nessuna offerta" / "Inizia creando la tua prima offerta"

src/components/admin/offers/OfferListClient.tsx

@@ -0,0 +1,158 @@
+"use client";
+
+import { useState, useMemo, useTransition } from "react";
+import { useRouter } from "next/navigation";
+import Link from "next/link";
+import { createOfferMacro } from "@/app/admin/offers/actions";
+import type { OfferListCard } from "@/lib/offer-queries";
+import { Button } from "@/components/ui/button";
+import { Badge } from "@/components/ui/badge";
+import { Input } from "@/components/ui/input";
+
+export function OfferListClient({
+  cards,
+  categoryOptions,
+}: {
+  cards: OfferListCard[];
+  categoryOptions: string[];
+}) {
+  const router = useRouter();
+  const [isPending, startTransition] = useTransition();
+  const [activeCategory, setActiveCategory] = useState<string | null>(null);
+  const [showArchived, setShowArchived] = useState(false);
+  const [showCreateForm, setShowCreateForm] = useState(false);
+  const [newOfferName, setNewOfferName] = useState("");
+
+  const filteredCards = useMemo(() => {
+    return cards.filter(
+      (c) =>
+        (activeCategory === null || c.category === activeCategory) &&
+        (showArchived || !c.is_archived)
+    );
+  }, [cards, activeCategory, showArchived]);
+
+  function handleCreateSubmit(formData: FormData) {
+    startTransition(async () => {
+      await createOfferMacro(formData);
+      setShowCreateForm(false);
+      setNewOfferName("");
+      router.refresh();
+    });
+  }
+
+  const createCta = (
+    <div className="flex flex-col items-end gap-2">
+      <Button
+        type="button"
+        className="bg-[#1A463C] text-white hover:bg-[#163a31]"
+        onClick={() => setShowCreateForm((v) => !v)}
+      >
+        + Nuova Offerta
+      </Button>
+      {showCreateForm && (
+        <form
+          action={handleCreateSubmit}
+          className="flex items-center gap-2 bg-white border border-[#e5e7eb] rounded-lg p-2"
+        >
+          <Input
+            name="internal_name"
+            required
+            placeholder="Nome offerta..."
+            value={newOfferName}
+            onChange={(e) => setNewOfferName(e.target.value)}
+            className="h-9 w-48"
+          />
+          <Button
+            type="submit"
+            size="sm"
+            disabled={isPending}
+            className="bg-[#1A463C] text-white hover:bg-[#163a31]"
+          >
+            Crea
+          </Button>
+        </form>
+      )}
+    </div>
+  );
+
+  return (
+    <div className="space-y-6">
+      {/* Page header */}
+      <div className="flex items-center justify-between">
+        <h2 className="text-[20px] font-semibold text-[#1a1a1a]">Offerte</h2>
+        {createCta}
+      </div>
+
+      {/* Filter row */}
+      <div className="flex flex-wrap items-center justify-between gap-4">
+        <div className="flex flex-wrap items-center gap-2">
+          <button
+            type="button"
+            onClick={() => setActiveCategory(null)}
+            className={`rounded-full border px-3 py-1 text-sm transition-colors ${
+              activeCategory === null
+                ? "border-[#1A463C] text-[#1A463C]"
+                : "border-[#e5e7eb] text-[#71717a]"
+            }`}
+          >
+            Tutti
+          </button>
+          {categoryOptions.map((category) => (
+            <button
+              key={category}
+              type="button"
+              onClick={() => setActiveCategory(category)}
+              className={`rounded-full border px-3 py-1 text-sm transition-colors ${
+                activeCategory === category
+                  ? "border-[#1A463C] text-[#1A463C]"
+                  : "border-[#e5e7eb] text-[#71717a]"
+              }`}
+            >
+              {category}
+            </button>
+          ))}
+        </div>
+
+        <label className="flex items-center gap-2 text-sm text-[#71717a]">
+          <input
+            type="checkbox"
+            checked={showArchived}
+            onChange={(e) => setShowArchived(e.target.checked)}
+            className="h-4 w-4 rounded border-[#e5e7eb]"
+          />
+          Mostra offerte archiviate
+        </label>
+      </div>
+
+      {/* Card grid / empty state */}
+      {filteredCards.length === 0 ? (
+        <div className="flex flex-col items-center justify-center gap-2 rounded-lg border border-[#e5e7eb] bg-white py-16 text-center">
+          <h3 className="text-[16px] font-semibold text-[#1a1a1a]">Nessuna offerta</h3>
+          <p className="text-sm text-[#71717a]">Inizia creando la tua prima offerta</p>
+          <div className="mt-2">{createCta}</div>
+        </div>
+      ) : (
+        <div className="grid grid-cols-1 gap-4 md:grid-cols-2 lg:grid-cols-3">
+          {filteredCards.map((card) => (
+            <Link
+              key={card.id}
+              href={`/admin/offers/${card.id}/edit`}
+              className="cursor-pointer rounded-lg border border-[#e5e7eb] bg-white p-4 transition-shadow hover:shadow-[0_4px_12px_rgba(0,0,0,0.08)]"
+            >
+              <h3 className="text-[16px] font-semibold text-[#1a1a1a]">{card.internal_name}</h3>
+              {card.description && (
+                <p className="mt-1 line-clamp-2 text-sm text-[#71717a]">{card.description}</p>
+              )}
+              <div className="mt-3 flex items-center gap-2">
+                {card.category && <Badge variant="secondary">{card.category}</Badge>}
+                {card.is_archived && (
+                  <span className="text-xs font-semibold text-[#dc2626]">Archiviata</span>
+                )}
+              </div>
+            </Link>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}