feat: chat globale revisioni + pagina statistiche admin

- Chat revisioni: rimuovi commenti inline da timeline/kanban, aggiungi
  ChatSection con feed cronologico + selector task opzionale (Invio per inviare)
  Bolle stile chat: Tu (destra, giallo) / iamcavalli (sinistra, verde)
  Tag task su ogni messaggio quando il messaggio non è generale
- API /api/client/comment: supporto entity_type "general" (entity_id = clientId)
- Pagina /admin/analytics: year selector ←→, 4 metric card (contrattualizzato,
  incassato, da incassare, clienti acquisiti), bar chart mensile incassato via CSS
- NavBar: link "Statistiche"

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/admin/NavBar.tsx

@@ -9,12 +9,12 @@ export function NavBar() {
     <nav className="bg-[#1A463C] px-6 py-3 flex items-center justify-between">
       <div className="flex items-center gap-6">
         <span className="font-bold text-white tracking-tight">iamcavalli</span>
-        <Link
-          href="/admin"
-          className="text-sm text-white/70 hover:text-white transition-colors"
-        >
+        <Link href="/admin" className="text-sm text-white/70 hover:text-white transition-colors">
           Clienti
         </Link>
+        <Link href="/admin/analytics" className="text-sm text-white/70 hover:text-white transition-colors">
+          Statistiche
+        </Link>
       </div>
       <Button
         variant="ghost"

src/components/admin/YearSelector.tsx

@@ -0,0 +1,70 @@
+"use client";
+
+import { useRouter } from "next/navigation";
+
+const MONTHS = ["Gen", "Feb", "Mar", "Apr", "Mag", "Giu", "Lug", "Ago", "Set", "Ott", "Nov", "Dic"];
+
+export function YearSelector({
+  currentYear,
+  availableYears,
+}: {
+  currentYear: number;
+  availableYears: number[];
+}) {
+  const router = useRouter();
+  const thisYear = new Date().getFullYear();
+
+  function go(y: number) {
+    router.push(`/admin/analytics?year=${y}`);
+  }
+
+  return (
+    <div className="flex items-center gap-3">
+      <button
+        onClick={() => go(currentYear - 1)}
+        className="w-8 h-8 rounded-lg border border-[#e5e7eb] flex items-center justify-center text-[#71717a] hover:border-[#1A463C] hover:text-[#1A463C] transition-colors"
+        aria-label="Anno precedente"
+      >
+        ←
+      </button>
+      <span className="text-lg font-bold text-[#1a1a1a] tabular-nums w-14 text-center">
+        {currentYear}
+      </span>
+      <button
+        onClick={() => go(currentYear + 1)}
+        disabled={currentYear >= thisYear}
+        className="w-8 h-8 rounded-lg border border-[#e5e7eb] flex items-center justify-center text-[#71717a] hover:border-[#1A463C] hover:text-[#1A463C] transition-colors disabled:opacity-30 disabled:cursor-not-allowed"
+        aria-label="Anno successivo"
+      >
+        →
+      </button>
+    </div>
+  );
+}
+
+export function MonthlyChart({ data, year }: { data: number[]; year: number }) {
+  const max = Math.max(...data, 1);
+
+  return (
+    <div className="bg-white rounded-xl border border-[#e5e7eb] p-6">
+      <h3 className="text-sm font-bold text-[#1a1a1a] mb-6">Incassato mese per mese — {year}</h3>
+      <div className="flex items-end gap-2 h-40">
+        {data.map((val, i) => {
+          const pct = Math.round((val / max) * 100);
+          return (
+            <div key={i} className="flex-1 flex flex-col items-center gap-1">
+              <div className="w-full flex flex-col justify-end" style={{ height: "120px" }}>
+                <div
+                  className="w-full rounded-t-md bg-[#1A463C] transition-all"
+                  style={{ height: `${pct}%`, minHeight: val > 0 ? "4px" : "0" }}
+                  title={`€ ${val.toLocaleString("it-IT", { minimumFractionDigits: 2 })}`}
+                />
+              </div>
+              <span className="text-[10px] text-[#71717a]">{MONTHS[i]}</span>
+            </div>
+          );
+        })}
+      </div>
+    </div>
+  );
+}