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/dashboards.ts

@@ -219,7 +219,7 @@ export const list = query({
     const dashboards = await ctx.db
       .query("dashboards")
       .withIndex("by_tenant", (q) => q.eq("tenantId", tenantId))
-      .collect()
+      .take(100)
 
     const filtered = (includeArchived ? dashboards : dashboards.filter((d) => !(d.isArchived ?? false))).sort(
       (a, b) => b.updatedAt - a.updatedAt,
@@ -230,7 +230,7 @@ export const list = query({
         const widgets = await ctx.db
           .query("dashboardWidgets")
           .withIndex("by_dashboard", (q) => q.eq("dashboardId", dashboard._id))
-          .collect()
+          .take(100)
         return {
           ...sanitizeDashboard(dashboard),
           widgetsCount: widgets.length,
@@ -256,14 +256,14 @@ export const get = query({
     const widgets = await ctx.db
       .query("dashboardWidgets")
       .withIndex("by_dashboard_order", (q) => q.eq("dashboardId", dashboardId))
-      .collect()
+      .take(100)
 
     widgets.sort((a, b) => a.order - b.order || a.createdAt - b.createdAt)
 
     const shares = await ctx.db
       .query("dashboardShares")
       .withIndex("by_dashboard", (q) => q.eq("dashboardId", dashboardId))
-      .collect()
+      .take(50)
 
     return {
       dashboard: sanitizeDashboard(dashboard),
@@ -457,7 +457,7 @@ export const updateLayout = mutation({
     const widgets = await ctx.db
       .query("dashboardWidgets")
       .withIndex("by_dashboard", (q) => q.eq("dashboardId", dashboardId))
-      .collect()
+      .take(100)
 
     const byKey = new Map<string, Doc<"dashboardWidgets">>()
     widgets.forEach((widget) => byKey.set(widget.widgetKey, widget))
@@ -518,7 +518,7 @@ export const addWidget = mutation({
     const existingWidgets = await ctx.db
       .query("dashboardWidgets")
       .withIndex("by_dashboard", (q) => q.eq("dashboardId", dashboardId))
-      .collect()
+      .take(100)
 
     const widgetId = await ctx.db.insert("dashboardWidgets", {
       tenantId,
@@ -617,7 +617,7 @@ export const ensureQueueSummaryWidget = mutation({
     const widgets = await ctx.db
       .query("dashboardWidgets")
       .withIndex("by_dashboard_order", (q) => q.eq("dashboardId", dashboardId))
-      .collect()
+      .take(100)
 
     widgets.sort((a, b) => a.order - b.order || a.createdAt - b.createdAt)
 
@@ -871,7 +871,7 @@ export const upsertShare = mutation({
     const existingShares = await ctx.db
       .query("dashboardShares")
       .withIndex("by_dashboard", (q) => q.eq("dashboardId", dashboardId))
-      .collect()
+      .take(50)
 
     const now = Date.now()
     let shareDoc = existingShares.find((share) => share.audience === audience)
@@ -917,7 +917,7 @@ export const revokeShareToken = mutation({
     const shares = await ctx.db
       .query("dashboardShares")
       .withIndex("by_dashboard", (q) => q.eq("dashboardId", dashboardId))
-      .collect()
+      .take(50)
 
     for (const share of shares) {
       if (share.audience === "public-link") {