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/users.ts

@@ -103,7 +103,7 @@ export const listAgents = query({
     const users = await ctx.db
       .query("users")
       .withIndex("by_tenant", (q) => q.eq("tenantId", tenantId))
-      .collect();
+      .take(5000);
 
     // Only internal staff (ADMIN/AGENT) should appear as responsáveis
     return users
@@ -128,7 +128,7 @@ export const listCustomers = query({
     const users = await ctx.db
       .query("users")
       .withIndex("by_tenant", (q) => q.eq("tenantId", tenantId))
-      .collect();
+      .take(5000);
 
     const allowed = users.filter((user) => {
       const role = (user.role ?? "COLLABORATOR").toUpperCase()
@@ -215,7 +215,7 @@ export const deleteUser = mutation({
     const comments = await ctx.db
       .query("ticketComments")
       .withIndex("by_author", (q) => q.eq("authorId", userId))
-      .collect();
+      .take(10000);
     if (comments.length > 0) {
       const authorSnapshot = {
         name: user.name,
@@ -243,7 +243,7 @@ export const deleteUser = mutation({
     const requesterTickets = await ctx.db
       .query("tickets")
       .withIndex("by_tenant_requester", (q) => q.eq("tenantId", user.tenantId).eq("requesterId", userId))
-      .collect();
+      .take(10000);
     if (requesterTickets.length > 0) {
       const requesterSnapshot = {
         name: user.name,
@@ -267,7 +267,7 @@ export const deleteUser = mutation({
     const directReports = await ctx.db
       .query("users")
       .withIndex("by_tenant_manager", (q) => q.eq("tenantId", user.tenantId).eq("managerId", userId))
-      .collect();
+      .take(1000);
     await Promise.all(
       directReports.map(async (report) => {
         await ctx.db.patch(report._id, { managerId: undefined });