Invalid origins and credentials CORS combination.

Location:  `SakhiCircle/backend/main.py` (Lines 46-52)  

Allows credentials and wildcard origins which is a security risk.
```python
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)
```