Retorna status da maquina mesmo sem sessao de chat ativa

A query getTicketSession agora sempre retorna machineOnline,
permitindo que o botao de chat seja habilitado corretamente
quando a maquina esta online mas nao ha sessao ativa.

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

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

src/components/tickets/ticket-summary-header.tsx

@@ -322,11 +322,11 @@ export function TicketSummaryHeader({ ticket }: TicketHeaderProps) {
       ? { ticketId: ticket.id as Id<"tickets">, viewerId: convexUserId as Id<"users"> }
       : "skip"
   ) as {
-    sessionId: Id<"liveChatSessions">
-    agentId: Id<"users">
+    sessionId: Id<"liveChatSessions"> | null
+    agentId: Id<"users"> | null
     agentName: string | null
-    startedAt: number
-    lastActivityAt: number
+    startedAt: number | null
+    lastActivityAt: number | null
     unreadByAgent: number
     machineOnline: boolean
   } | null | undefined