feat: enhance organization management; add member registration and validation, update user registration flow, and improve enum handling

tests/api/v1/test_auth.py

@@ -51,6 +51,57 @@ async def test_register_user_creates_organization_membership(
         assert membership.role == OrganizationRole.OWNER
 
 
+@pytest.mark.asyncio
+async def test_register_user_without_organization_succeeds(
+    session_factory: async_sessionmaker[AsyncSession],
+    client: AsyncClient,
+) -> None:
+    payload = {
+        "email": "solo-user@example.com",
+        "password": "StrongPass123!",
+        "name": "Solo User",
+    }
+
+    response = await client.post("/api/v1/auth/register", json=payload)
+
+    assert response.status_code == 201
+
+    async with session_factory() as session:
+        user = await session.scalar(select(User).where(User.email == payload["email"]))
+        assert user is not None
+
+        membership = await session.scalar(
+            select(OrganizationMember).where(OrganizationMember.user_id == user.id)
+        )
+        assert membership is None
+
+
+@pytest.mark.asyncio
+async def test_register_fails_when_organization_exists(
+    client: AsyncClient,
+) -> None:
+    payload = {
+        "email": "owner-one@example.com",
+        "password": "StrongPass123!",
+        "name": "Owner One",
+        "organization_name": "Duplicate Org",
+    }
+    response = await client.post("/api/v1/auth/register", json=payload)
+    assert response.status_code == 201
+
+    duplicate_payload = {
+        "email": "owner-two@example.com",
+        "password": "StrongPass123!",
+        "name": "Owner Two",
+        "organization_name": "Duplicate Org",
+    }
+
+    duplicate_response = await client.post("/api/v1/auth/register", json=duplicate_payload)
+
+    assert duplicate_response.status_code == 409
+    assert duplicate_response.json()["detail"] == "Organization already exists"
+
+
 @pytest.mark.asyncio
 async def test_login_endpoint_returns_token_for_valid_credentials(
     session_factory: async_sessionmaker[AsyncSession],