fix(openai-sdk-python): don't fail get_profile for users with no memories

[Atharvsinh-codez]

What was wrong

For a user who has no stored memories yet, the API returns a null profile (this is the same case as #1027, which was fixed for the pipecat package). SupermemoryTools.get_profile passed that straight to _model_to_dict, which raises TypeError for None. The broad except then turned it into a failed tool call:

{'success': False, 'error': 'Profile fetch failed: Unsupported SDK response type: NoneType'}

So the model sees a failing getProfile call for every new user, instead of an empty profile.

Repro

tools = SupermemoryTools("key", {"container_tags": ["new-user"]})
tools.client.profile = AsyncMock(return_value=SimpleNamespace(profile=None, search_results=None))
await tools.get_profile()

On main this returns the error above. With this change it returns success=True and profile={"static": [], "dynamic": []}.

The fix

When response.profile is None, return an empty profile. This matches what the cartesia and pipecat packages already do. search_results was already handled for None, so it is unchanged.

I only changed get_profile. I didn't touch document_list, since I haven't seen the API return a null pagination.

Tests

Added test_get_profile_handles_user_with_no_memories in tests/test_tools.py. It fails on main and passes with the fix. The full tests/ run gives 32 passed, 11 skipped (the skipped ones need a real API key), and black --check is clean.