Implementa sistema de chat em tempo real entre agente e cliente

- Adiciona tabela liveChatSessions no schema Convex
- Cria convex/liveChat.ts com mutations e queries para chat
- Adiciona API routes para maquinas (sessions, messages, poll)
- Cria modulo chat.rs no Tauri com ChatRuntime e polling
- Adiciona comandos de chat no lib.rs (start/stop polling, open/close window)
- Cria componentes React do chat widget (ChatWidget, types)
- Adiciona botao "Iniciar Chat" no dashboard (ticket-chat-panel)
- Implementa menu de chat no system tray
- Polling de 2 segundos para maior responsividade
- Janela de chat flutuante, frameless, always-on-top

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

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

convex/tickets.ts

@@ -2956,12 +2956,59 @@ export const listChatMessages = query({
       .withIndex("by_ticket_created", (q) => q.eq("ticketId", ticketId))
       .collect()
 
+    // Verificar maquina e sessao de chat ao vivo
+    let liveChat: {
+      hasMachine: boolean
+      machineOnline: boolean
+      machineHostname: string | null
+      activeSession: {
+        sessionId: Id<"liveChatSessions">
+        agentId: Id<"users">
+        agentName: string | null
+        startedAt: number
+        unreadByAgent: number
+      } | null
+    } = {
+      hasMachine: false,
+      machineOnline: false,
+      machineHostname: null,
+      activeSession: null,
+    }
+
+    if (ticketDoc.machineId) {
+      const machine = await ctx.db.get(ticketDoc.machineId)
+      if (machine) {
+        const fiveMinutesAgo = now - 5 * 60 * 1000
+        liveChat.hasMachine = true
+        liveChat.machineOnline = Boolean(machine.lastHeartbeatAt && machine.lastHeartbeatAt > fiveMinutesAgo)
+        liveChat.machineHostname = machine.hostname
+
+        // Verificar sessao ativa
+        const activeSession = await ctx.db
+          .query("liveChatSessions")
+          .withIndex("by_ticket", (q) => q.eq("ticketId", ticketId))
+          .filter((q) => q.eq(q.field("status"), "ACTIVE"))
+          .first()
+
+        if (activeSession) {
+          liveChat.activeSession = {
+            sessionId: activeSession._id,
+            agentId: activeSession.agentId,
+            agentName: activeSession.agentSnapshot?.name ?? null,
+            startedAt: activeSession.startedAt,
+            unreadByAgent: activeSession.unreadByAgent ?? 0,
+          }
+        }
+      }
+    }
+
     return {
       ticketId: String(ticketId),
       chatEnabled,
       status,
       canPost,
       reopenDeadline: ticketDoc.reopenDeadline ?? null,
+      liveChat,
       messages: messages
         .sort((a, b) => a.createdAt - b.createdAt)
         .map((message) => ({