refactor: integrate Alembic, restructure project, and clean up

- Add Alembic configuration (alembic.ini, env.py) for database migrations
- Remove legacy wheel.db and unnecessary __pycache__ files
- Delete models.py to separate SQLAlchemy and Pydantic concerns
- Restructure main.py to use modular API routers (user/admin)
- Introduce config backend for centralized settings management

backend/main.py

@@ -21,59 +21,7 @@ app.add_middleware(
     allow_headers=["*"],
 )
 
-# Database Session
-def get_db():
-    db = SessionLocal()
 
-    try:
-        yield db
-    finally:
-        db.close()
 
-# GET ITEMS
-@app.get("/items", response_model=list[schemas.ItemResponse])
-def get_items(db: Session = Depends(get_db)):
-    return crud.get_items(db)
-
-# CREATE ITEM
-@app.post("/items", response_model=schemas.ItemResponse)
-def create_item(
-    item: schemas.ItemCreate,
-    db: Session = Depends(get_db)
-):
-    return crud.create_item(db, item.title)
-
-# DELETE ITEM
-@app.delete("/items/{item_id}")
-def delete_item(
-    item_id: int,
-    db: Session = Depends(get_db)
-):
-    item = crud.delete_item(db, item_id)
-
-    if not item:
-        raise HTTPException(
-            status_code=404,
-            detail="Item not found"
-        )
-
-    return {"message": "Item deleted"}
-
-# SPIN
-@app.post("/spin")
-def spin(db: Session = Depends(get_db)):
-
-    winner = crud.spin_wheel(db)
-
-    if not winner:
-        raise HTTPException(
-            status_code=400,
-            detail="No items available"
-        )
-
-    return {
-        "winner": {
-            "id": winner.id,
-            "title": winner.title
-        }
-    }
+app.include_router(user_router)
+app.include_router(admin_router)