Phase 2: Database e API Layer

- Configurado Prisma 7 com multiSchema para staging database
- Models: Site, GA4DailyTraffic, GA4TrafficSources, GSCSearchPerformance
- Created lib utilities (prisma.ts, utils.ts) com formatação PT-PT
- API routes implementadas:
  * GET /api/sites - lista sites activos
  * GET /api/metrics/[siteId]?period=30d - métricas agregadas + charts
  * GET /api/health - health check com conexão DB

Métricas incluem:
- KPIs: visitors, sessions, pageViews, newUsers com % change
- Charts: dailyTraffic, trafficSources, topQueries (GSC)
- Comparação período anterior para trends

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

prisma/schema.prisma

@@ -0,0 +1,84 @@
+// Prisma schema for BI Descomplicar
+// Maps to existing PostgreSQL staging database
+
+datasource db {
+  provider = "postgresql"
+  schemas  = ["staging"]
+}
+
+generator client {
+  provider        = "prisma-client-js"
+  previewFeatures = ["multiSchema"]
+}
+
+// Sites configuration
+model Site {
+  id              Int     @id @default(autoincrement())
+  siteName        String  @map("site_name")
+  ga4PropertyId   String? @map("ga4_property_id")
+  gscSiteUrl      String? @map("gsc_site_url")
+  deskProjectId   Int?    @map("desk_project_id")
+  deskClientId    Int?    @map("desk_client_id")
+  active          Boolean @default(true)
+
+  @@map("sites_config")
+  @@schema("staging")
+}
+
+// GA4 Daily Traffic
+model GA4DailyTraffic {
+  id                   Int      @id @default(autoincrement())
+  propertyId           String   @map("property_id")
+  siteName             String?  @map("site_name")
+  date                 DateTime @db.Date
+  pagePath             String?  @map("page_path")
+  activeUsers          Int      @default(0) @map("active_users")
+  sessions             Int      @default(0)
+  pageViews            Int      @default(0) @map("page_views")
+  engagementRate       Decimal  @default(0) @map("engagement_rate") @db.Decimal(5, 4)
+  avgSessionDuration   Decimal  @default(0) @map("avg_session_duration") @db.Decimal(10, 2)
+  bounceRate           Decimal  @default(0) @map("bounce_rate") @db.Decimal(5, 4)
+  newUsers             Int      @default(0) @map("new_users")
+  createdAt            DateTime @default(now()) @map("created_at")
+
+  @@unique([propertyId, date, pagePath])
+  @@map("ga4_daily_traffic")
+  @@schema("staging")
+}
+
+// GA4 Traffic Sources
+model GA4TrafficSources {
+  id                Int      @id @default(autoincrement())
+  propertyId        String   @map("property_id")
+  siteName          String?  @map("site_name")
+  date              DateTime @db.Date
+  sessionSource     String?  @map("session_source")
+  sessionMedium     String?  @map("session_medium")
+  sessionCampaign   String?  @map("session_campaign")
+  sessions          Int      @default(0)
+  newUsers          Int      @default(0) @map("new_users")
+  engagedSessions   Int      @default(0) @map("engaged_sessions")
+  createdAt         DateTime @default(now()) @map("created_at")
+
+  @@unique([propertyId, date, sessionSource, sessionMedium])
+  @@map("ga4_traffic_sources")
+  @@schema("staging")
+}
+
+// GSC Search Performance
+model GSCSearchPerformance {
+  id          Int      @id @default(autoincrement())
+  siteUrl     String   @map("site_url")
+  date        DateTime @db.Date
+  query       String
+  page        String?
+  clicks      Int      @default(0)
+  impressions Int      @default(0)
+  ctr         Decimal  @default(0) @db.Decimal(5, 4)
+  position    Decimal  @default(0) @db.Decimal(6, 2)
+  createdAt   DateTime @default(now()) @map("created_at")
+
+  @@unique([siteUrl, date, query, page])
+  @@map("gsc_search_performance")
+  @@schema("staging")
+}