PY API - Return values that are dicts: instance methods unusable on the client

Calling any RPC that returns a dict (e.g. publish_request returning the WebRTC response) and then doing r.get("data"), r.keys(), r.values() etc. from the client side fails with:

AttributeError: cannot access 'get'

Dunder methods (__getitem__, __repr__, __contains__, __iter__, ...) are exposed by RPyC's netref class even when allow_public_attrs=False.

resp.get('data')  → AttributeError: cannot access 'get'
resp['data']      → KeyError: 'data'   (server-side dict really had no 'data' key — this is normal Python)
repr(resp)        → "{'status': 'ok', 'message': 'Fake publish'}"

for k, v in resp.items() and resp.get(k, default) style code is broken; bracket indexing, len(), in, iteration, and printing all work.

the dict is a netref, and the client-side VoidService doesn't allow public attribute reads. same issue as https://github.com/dimensionalOS/dimos/issues/1965

Synced from DIM-837 by summer