fix(convex): corrigir memory leak com .collect() sem limite e adicionar otimizacoes

Problema: Convex backend consumindo 16GB+ de RAM causando OOM kills

Correcoes aplicadas:
- Substituido todos os .collect() por .take(LIMIT) em 27+ arquivos
- Adicionado indice by_usbPolicyStatus para otimizar query de maquinas
- Corrigido N+1 problem em alerts.ts usando Map lookup
- Corrigido full table scan em usbPolicy.ts
- Corrigido subscription leaks no frontend (tickets-view, use-ticket-categories)
- Atualizado versao do Convex backend para precompiled-2025-12-04-cc6af4c

Arquivos principais modificados:
- convex/*.ts - limites em todas as queries .collect()
- convex/schema.ts - novo indice by_usbPolicyStatus
- convex/alerts.ts - N+1 fix com Map
- convex/usbPolicy.ts - uso do novo indice
- src/components/tickets/tickets-view.tsx - skip condicional
- src/hooks/use-ticket-categories.ts - skip condicional

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

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

convex/_generated/api.d.ts

@@ -25,6 +25,7 @@ import type * as fields from "../fields.js";
 import type * as files from "../files.js";
 import type * as incidents from "../incidents.js";
 import type * as invites from "../invites.js";
+import type * as liveChat from "../liveChat.js";
 import type * as machines from "../machines.js";
 import type * as metrics from "../metrics.js";
 import type * as migrations from "../migrations.js";
@@ -74,6 +75,7 @@ declare const fullApi: ApiFromModules<{
   files: typeof files;
   incidents: typeof incidents;
   invites: typeof invites;
+  liveChat: typeof liveChat;
   machines: typeof machines;
   metrics: typeof metrics;
   migrations: typeof migrations;