bug: Python SDK omits credential-driver bindings #4759

User Story

I use OpenShell with an external credential driver written in Python and need its generated gRPC bindings.

Problem Statement

The Python wheel omits bindings for credential_driver.proto and extension.proto, preventing normal CredentialDriverServicer registration.

Impact / Why This Matters

Driver implementations must generate bindings separately or maintain a descriptor-pool compatibility layer.

Acceptance Criteria

• The wheel includes both protocols’ message modules, gRPC bindings, and type stubs.
• Imports work and share the SDK’s existing message descriptors.
• A generated client/server RPC exchange passes.

Reproduction Steps

With OpenShell 0.1.2 installed, this import fails:

from openshell._proto import credential_driver_pb2_grpc

Environment

OpenShell 0.1.2 Python wheel; external Python credential-driver integration.