Add Paddle webhook ingestion foundation

backend/prisma/migrations/20260709110000_milestone1221_paddle_webhook_ingestion_foundation/migration.sql

@@ -0,0 +1,23 @@
+-- CreateEnum
+CREATE TYPE "BillingWebhookStatus" AS ENUM ('RECEIVED', 'DUPLICATE', 'FAILED');
+
+-- CreateTable
+CREATE TABLE "billing_webhook_events" (
+    "id" UUID NOT NULL,
+    "provider" "BillingProvider" NOT NULL,
+    "provider_event_id" TEXT NOT NULL,
+    "event_type" TEXT NOT NULL,
+    "payload" JSONB NOT NULL,
+    "received_at" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "processed_at" TIMESTAMP(3),
+    "status" "BillingWebhookStatus" NOT NULL,
+    "error_message" TEXT,
+    "created_at" TIMESTAMP(3) NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updated_at" TIMESTAMP(3) NOT NULL,
+
+    CONSTRAINT "billing_webhook_events_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "billing_webhook_events_provider_provider_event_id_key"
+ON "billing_webhook_events"("provider", "provider_event_id");

backend/prisma/schema.prisma

@@ -349,6 +349,23 @@ model UserEntitlement {
   @@map("user_entitlements")
 }
 
+model BillingWebhookEvent {
+  id              String               @id @default(uuid()) @db.Uuid
+  provider        BillingProvider
+  providerEventId String               @map("provider_event_id")
+  eventType       String               @map("event_type")
+  payload         Json
+  receivedAt      DateTime             @default(now()) @map("received_at")
+  processedAt     DateTime?            @map("processed_at")
+  status          BillingWebhookStatus
+  errorMessage    String?              @map("error_message")
+  createdAt       DateTime             @default(now()) @map("created_at")
+  updatedAt       DateTime             @updatedAt @map("updated_at")
+
+  @@unique([provider, providerEventId])
+  @@map("billing_webhook_events")
+}
+
 enum SubscriptionStatus {
   TRIAL
   ACTIVE
@@ -366,6 +383,12 @@ enum BillingProvider {
   PADDLE
 }
 
+enum BillingWebhookStatus {
+  RECEIVED
+  DUPLICATE
+  FAILED
+}
+
 enum UserAccountKind {
   LEGACY_DEFAULT
   GUEST