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

backend/app/api/deps.py

@@ -0,0 +1,42 @@
+from typing import Annotated
+
+from fastapi import Depends, HTTPException, status
+from fastapi.security import OAuth2PasswordBearer
+from jose import JWTError
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+
+from app.core.security import decode_token
+from app.db.session import get_db
+from app.models.domain import User
+
+
+oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/v1/auth/login")
+DbSession = Annotated[Session, Depends(get_db)]
+
+
+def current_user(db: DbSession, token: Annotated[str, Depends(oauth2_scheme)]) -> User:
+    try:
+        payload = decode_token(token)
+    except JWTError as exc:
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid token") from exc
+    if payload.get("typ") != "access":
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid token type")
+    user = db.scalar(select(User).where(User.id == payload["sub"], User.is_active.is_(True)))
+    if not user:
+        raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Inactive or missing user")
+    return user
+
+
+CurrentUser = Annotated[User, Depends(current_user)]
+
+
+def require_permission(permission: str):
+    def dependency(user: CurrentUser) -> User:
+        permissions = {permission for role in user.roles for permission in role.permissions}
+        if "*" not in permissions and permission not in permissions:
+            raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Missing permission")
+        return user
+
+    return dependency
+