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

apps/api/src/auth/auth.controller.ts

@@ -1,7 +1,9 @@
-import { Body, Controller, Get, HttpCode, HttpStatus, Post, Req, UseGuards } from "@nestjs/common";
+import { Body, Controller, Get, HttpCode, HttpStatus, NotFoundException, Post, Req, UseGuards } from "@nestjs/common";
 import type { FastifyRequest } from "fastify";
+import { getPrismaClient } from "@b2bcall/database";
 import {
   changePassword,
+  isPlatformUser,
   listUserTenants,
   login,
   logout,
@@ -44,6 +46,18 @@ export class AuthController {
     await logout(user.sessionId);
   }
 
+  @UseGuards(JwtAuthGuard)
+  @Get("me")
+  async me(@CurrentUser() user: AccessTokenClaims) {
+    const prisma = getPrismaClient();
+    const dbUser = await prisma.user.findUnique({
+      where: { id: user.sub },
+      select: { id: true, email: true, name: true },
+    });
+    if (!dbUser) throw new NotFoundException();
+    return { ...dbUser, isPlatformUser: await isPlatformUser(user.sub) };
+  }
+
   @UseGuards(JwtAuthGuard)
   @Get("tenants")
   async tenants(@CurrentUser() user: AccessTokenClaims) {