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/ticketFormSettings.ts

@@ -45,7 +45,7 @@ export const list = query({
     const settings = await ctx.db
       .query("ticketFormSettings")
       .withIndex("by_tenant", (q) => q.eq("tenantId", tenantId))
-      .collect()
+      .take(100)
     return settings
       .filter((setting) => !normalizedTemplate || setting.template === normalizedTemplate)
       .map((setting) => ({
@@ -143,7 +143,7 @@ async function findExisting(
   const candidates = await ctx.db
     .query("ticketFormSettings")
     .withIndex("by_tenant_template_scope", (q) => q.eq("tenantId", tenantId).eq("template", template).eq("scope", scope))
-    .collect()
+    .take(100)
 
   return candidates.find((setting) => {
     if (scope === "tenant") return true