Implement backend API and database services in Docker setup

- Added a new `api` service for the NestJS backend, including health checks and dependencies on PostgreSQL, Redis, and MinIO.
- Introduced PostgreSQL and Redis services with health checks and configurations for data persistence.
- Added MinIO for S3-compatible object storage and a one-shot service to initialize required buckets.
- Updated the Nginx configuration to proxy requests to the new backend API and MinIO storage.
- Enhanced the Dockerfile to support the new API environment variables and configurations.
- Updated the `package.json` and `package-lock.json` to include new dependencies for QR code generation and other utilities.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/src/subscriptions/dto/flash-webhook-event.dto.ts

@@ -0,0 +1,37 @@
+import { flashEventType } from '../enums/flash-event.enum';
+import { SubscriptionType } from '../enums/types.enum';
+
+export interface FlashWebhookData {
+  public_key: string;
+  name: string;
+  email: string;
+  about?: string;
+  picture_url: string;
+  user_plan: SubscriptionType;
+  user_plan_id: number;
+  signup_date: string;
+  next_payment_date: string;
+  failed_payment_date: string;
+  transaction_id: string;
+  transaction_amount: number;
+  transaction_currency: string;
+  transaction_date: string;
+  external_uuid: string;
+}
+
+export interface FlashWebhookEvent {
+  version: string;
+  eventType: {
+    id: number;
+    name: (typeof flashEventType)[number];
+  };
+  user_public_key: string;
+  exp: number; // Expiration time as a Unix timestamp
+  // iat: number; // Issued at time as a Unix timestamp
+}
+
+export interface Flash {
+  event: FlashWebhookEvent;
+  data: FlashWebhookData;
+  type: SubscriptionType;
+}