feat(billing): rating engine, fechamento de periodo, dashboard platform (fase 22)

Fecha a orquestracao de Billing (agente.md secao 120-139) sobre o schema/
RatingEngine puro ja existentes: escritores do ledger UsageEvent
(CALL_SECONDS no CDR, ACTIVE_DAY via sweep diario), closeBillingPeriod/
reopenBillingPeriod (fechamento imutavel com audit trail), e os
controllers de price books/rate decks/plan versions/subscriptions/
periods/statements. Corrige 2 bugs reais de RLS achados no teste ponta a
ponta (reopen sem tenant context, subscriptions sem withTenantContext) e
adiciona teste unitario do RatingEngine (17 casos).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EWHKmcVJtstQFErbZ1AanY

packages/billing/tsconfig.json

@@ -0,0 +1,8 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "outDir": "dist",
+    "rootDir": "src"
+  },
+  "include": ["src"]
+}