feat: Add WonderQ-MiniAPP Public API documentation

- Introduced a comprehensive API contract for the WonderQ-MiniAPP, detailing endpoints for site configuration, product listings, and lead submissions.
- Defined data types for various entities including HeroSlide, Destination, Theme, CtaBanner, PublicProduct, and more.
- Specified request and response formats, including error handling guidelines.

chore: Update requirements to include python-multipart

- Added python-multipart dependency to requirements.txt for handling file uploads.

test: Implement API contract tests

- Created test suite for API contracts, validating serializers and endpoints for public products and leads.
- Included tests for destination and product serializers, ensuring correct data handling and validation.

test: Add configuration tests for OSS settings

- Implemented tests to verify that OSS settings are correctly loaded from environment variables.

.env.example

@@ -3,3 +3,7 @@ JWT_SECRET="replace-with-a-long-random-secret-before-production"
 PORT=4000
 LOG_LEVEL="info"
 CORS_ORIGINS="*"
+OSS_ACCESS_KEY_ID="your-oss-access-key-id"
+OSS_ACCESS_KEY_SECRET="your-oss-access-key-secret"
+OSS_ENDPOINT="your-oss-endpoint"
+OSS_BUCKET_NAME="your-oss-bucket-name"