Feat/music licensing solution

[OssFit]

Description

This PR implements the complete backend for the Music Licensing Workflow system. It provides a RESTful API to manage Movies, Scenes, Songs, and Tracks, including a state machine for licensing status and real-time updates via WebSockets.

Key Features:

• Architecture: Modular NestJS application with Repository Pattern.
• Database: PostgreSQL with Prisma ORM (v5).
• Real-time: WebSocket Gateway integrated with Redis Pub/Sub for scalable event broadcasting.
• Workflow: State machine logic for Track licensing (PENDING -> NEGOTIATING -> APPROVED/REJECTED).
• Infrastructure: Fully containerized with Docker and Docker Compose (App, DB, Redis).
• CI/CD: GitHub Actions pipeline for automated testing.
• Documentation: Swagger UI and comprehensive README.

Fixes # (Music Licensing Workflow Challenge)

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

How Has This Been Tested?

I have implemented both Unit and End-to-End tests to verify the system's reliability.

• Unit Tests (npm run test): Verified individual services and controllers, specifically mocking Redis and Database dependencies. Confirmed State Machine transitions logic in TracksService.
• E2E Tests (npm run test:e2e): Verified the complete user flow: Create Movie -> Create Scene -> Create Song -> Create Track -> Update Track Status -> Verify Real-time Event.

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas (e.g., State Machine, Redis integration)
• I have made corresponding changes to the documentation (README, Swagger)
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules
• I have checked my code and corrected any misspellings