fix: respect root_path in FastAPI docs

tests/test_docs_root_path.py

@@ -0,0 +1,24 @@
+from fastapi.testclient import TestClient
+
+from app.main import create_app
+from app.core.config import Settings
+
+
+def test_docs_uses_root_path_for_openapi_url() -> None:
+    app = create_app(settings_factory=lambda: Settings(root_path="/portfolio-hub"))
+
+    with TestClient(app) as client:
+        response = client.get("/docs")
+
+    assert response.status_code == 200
+    assert "url: '/portfolio-hub/openapi.json'" in response.text
+
+
+def test_openapi_is_served_under_root_path() -> None:
+    app = create_app(settings_factory=lambda: Settings(root_path="/portfolio-hub"))
+
+    with TestClient(app) as client:
+        response = client.get("/portfolio-hub/openapi.json")
+
+    assert response.status_code == 200
+    assert response.json()["info"]["title"] == "PortfolioHub"