fix: add conftest.py with shared TestClient fixture for pytest

Author: DHANUSHGCODE

backend/tests/conftest.py

@@ -0,0 +1,10 @@
+import pytest
+from fastapi.testclient import TestClient
+from backend.main import app
+
+
+@pytest.fixture(scope="module")
+def client():
+    """Provide a TestClient for all tests in this module."""
+    with TestClient(app) as c:
+        yield c