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/categorySlas.ts

@@ -84,7 +84,7 @@ export const get = query({
     const records = await ctx.db
       .query("categorySlaSettings")
       .withIndex("by_tenant_category", (q) => q.eq("tenantId", tenantId).eq("categoryId", categoryId))
-      .collect()
+      .take(100)
 
     return {
       categoryId,
@@ -119,7 +119,7 @@ export const save = mutation({
     const existing = await ctx.db
       .query("categorySlaSettings")
       .withIndex("by_tenant_category", (q) => q.eq("tenantId", tenantId).eq("categoryId", categoryId))
-      .collect()
+      .take(100)
     await Promise.all(existing.map((record) => ctx.db.delete(record._id)))
 
     const now = Date.now()