feat(desktop): implementa Convex React subscriptions para chat em tempo real

- Adiciona ConvexMachineProvider para autenticacao via machine token
- Cria hooks customizados (useMachineSessions, useMachineMessages, etc)
- Refatora ChatWidget e ChatHubWidget para usar useQuery/useMutation
- Remove polling e dependencia de Tauri events para mensagens
- Adiciona copia local dos arquivos _generated do Convex
- Remove componentes obsoletos (ChatSessionItem, ChatSessionList)

Beneficios:
- Tempo real verdadeiro via WebSocket (sem polling)
- Melhor escalabilidade e performance
- Codigo mais simples e maintivel
- Consistencia de estado entre multiplas janelas

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/desktop/src/chat/index.tsx

@@ -1,20 +1,63 @@
+import { ConvexProvider } from "convex/react"
 import { ChatWidget } from "./ChatWidget"
 import { ChatHubWidget } from "./ChatHubWidget"
+import { ConvexMachineProvider, useConvexMachine } from "./ConvexMachineProvider"
+import { Loader2 } from "lucide-react"
+
+function ChatAppContent() {
+  const { client, isReady, error } = useConvexMachine()
 
-export function ChatApp() {
   // Obter ticketId e ticketRef da URL
   const params = new URLSearchParams(window.location.search)
   const ticketId = params.get("ticketId")
   const ticketRef = params.get("ticketRef")
   const isHub = params.get("hub") === "true"
 
+  // Aguardar cliente Convex estar pronto
+  if (!isReady || !client) {
+    if (error) {
+      return (
+        <div className="pointer-events-none flex h-full w-full items-end justify-end bg-transparent p-2">
+          <div className="pointer-events-auto flex items-center gap-2 rounded-full bg-red-100 px-4 py-2 text-red-600 shadow-lg">
+            <span className="text-sm font-medium">Erro: {error}</span>
+          </div>
+        </div>
+      )
+    }
+
+    return (
+      <div className="pointer-events-none flex h-full w-full items-end justify-end bg-transparent p-2">
+        <div className="pointer-events-auto flex items-center gap-2 rounded-full bg-slate-200 px-4 py-2 text-slate-600 shadow-lg">
+          <Loader2 className="size-4 animate-spin" />
+          <span className="text-sm font-medium">Conectando...</span>
+        </div>
+      </div>
+    )
+  }
+
   // Modo hub - lista de todas as sessoes
   if (isHub || !ticketId) {
-    return <ChatHubWidget />
+    return (
+      <ConvexProvider client={client}>
+        <ChatHubWidget />
+      </ConvexProvider>
+    )
   }
 
   // Modo chat - conversa de um ticket especifico
-  return <ChatWidget ticketId={ticketId} ticketRef={ticketRef ? Number(ticketRef) : undefined} />
+  return (
+    <ConvexProvider client={client}>
+      <ChatWidget ticketId={ticketId} ticketRef={ticketRef ? Number(ticketRef) : undefined} />
+    </ConvexProvider>
+  )
+}
+
+export function ChatApp() {
+  return (
+    <ConvexMachineProvider>
+      <ChatAppContent />
+    </ConvexMachineProvider>
+  )
 }
 
 export { ChatWidget }