chore: initial project setup with backend, frontend, CI/CD, and documentation

Add complete NexaFabric project structure including:
- FastAPI backend with SQLAlchemy models, JWT auth, RBAC, audit logging, and provider interfaces
- React + TypeScript frontend with Vite, Tailwind CSS, TanStack Query, and Zustand
- Docker Compose configuration for PostgreSQL, Redis, API, worker, frontend, and nginx
- GitHub Actions and GitLab CI workflows for testing, linting, building, and security scanning
- Environment

docs/backup-restore.md

@@ -0,0 +1,18 @@
+# Backup And Restore
+
+Back up:
+
+- PostgreSQL database
+- Environment file and secret material
+- Reverse proxy configuration
+- Optional worker queue state
+
+Restore:
+
+1. Stop API and workers.
+2. Restore PostgreSQL.
+3. Restore `.env` and encryption keys.
+4. Start PostgreSQL and Redis.
+5. Start API and workers.
+6. Run health checks and verify audit log continuity.
+