feat: client edit/delete/archive + time tracker + analytics time section

Schema:
- clients.archived boolean (default false)
- time_entries table (client_id, started_at, ended_at, duration_seconds)

Client management:
- /admin/clients/[id]/edit — form pre-compilato con nome, brand, brief
- ClientActions: Modifica / Archivia / Elimina con doppia conferma
- setClientArchived: toggle archiviazione senza perdere dati
- deleteClient: elimina con cascade, redirect a /admin
- Admin list: toggle "Mostra archiviati" via ?archived=1, righe archiviate opache

Time tracker:
- startTimer: crea sessione, ferma automaticamente quella precedente
- stopTimer: chiude sessione, calcola duration_seconds
- TimerCell: ▶/⏹ per ogni cliente, contatore live in secondi, totale cumulativo
- Una sola sessione attiva alla volta su tutta la lista

Analytics:
- Sezione "Fatturato" (invariata) + sezione "Tempo tracciato" separata
- Ore totali per anno + barre orizzontali per cliente
- getTotalTrackedHours, getTimeByClient queries

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

src/app/admin/clients/[id]/page.tsx

@@ -6,6 +6,7 @@ import { PaymentsTab } from "@/components/admin/tabs/PaymentsTab";
 import { DocumentsTab } from "@/components/admin/tabs/DocumentsTab";
 import { CommentsTab } from "@/components/admin/tabs/CommentsTab";
 import { PhasesViewToggle } from "@/components/admin/kanban/PhasesViewToggle";
+import { ClientActions } from "@/components/admin/ClientActions";
 import Link from "next/link";
 
 export const revalidate = 0;
@@ -19,28 +20,37 @@ export default async function ClientDetailPage({
   const detail = await getClientFullDetail(id);
   if (!detail) notFound();
 
-  const { client, phases, payments, documents, notes, comments } = detail;
+  const { client, phases, payments, documents, comments } = detail;
 
   return (
     <div>
       <div className="mb-4">
-        <Link href="/admin" className="text-sm text-gray-500 hover:text-gray-700">
+        <Link href="/admin" className="text-sm text-[#71717a] hover:text-[#1a1a1a]">
           ← Clienti
         </Link>
       </div>
-      <div className="mb-6 flex items-start justify-between">
+
+      <div className="mb-6 flex items-start justify-between gap-4 flex-wrap">
         <div>
-          <h1 className="text-2xl font-bold text-gray-900">{client.name}</h1>
-          <p className="text-sm text-gray-500">{client.brand_name}</p>
+          <h1 className="text-2xl font-bold text-[#1a1a1a]">{client.name}</h1>
+          <p className="text-sm text-[#71717a]">{client.brand_name}</p>
+          {client.archived && (
+            <span className="inline-block mt-1 text-xs font-medium bg-[#f4f4f5] text-[#71717a] px-2 py-0.5 rounded-full">
+              Archiviato
+            </span>
+          )}
+        </div>
+        <div className="flex flex-col items-end gap-2">
+          <a
+            href={`/c/${client.token}`}
+            target="_blank"
+            rel="noopener noreferrer"
+            className="text-xs text-[#1A463C] hover:underline font-mono bg-[#1A463C]/5 px-2 py-1 rounded"
+          >
+            Link cliente →
+          </a>
+          <ClientActions clientId={client.id} archived={client.archived ?? false} />
         </div>
-        <a
-          href={`/c/${client.token}`}
-          target="_blank"
-          rel="noopener noreferrer"
-          className="text-xs text-blue-600 hover:underline font-mono bg-blue-50 px-2 py-1 rounded"
-        >
-          Link cliente →
-        </a>
       </div>
 
       <Tabs defaultValue="phases" className="w-full">