[moetemp]

What changed?

This PR makes generated Python resources with methods plain classes, so the payload converter refuses them.

• With Add independent Python client generation and explicit API targets temporalio/nexgen#344, a resource is a dataclass. So a client Stream encodes as its stream and created fields, and decodes as a Workflow Stream whose publish, read and close work.
• A resource with methods is now a plain class with the same __init__ and attributes, and __eq__ and __repr__ over its identity fields. The JSON converter refuses it in both directions. Code passes the identity fields, such as the stream sample's StreamRef, and builds the handle with the factory.
• Workflow calls decode a direct resource result as its identity record, such as UserData, and then build the handle, as the client calls already do.
• A resource with no methods, such as WorkflowHandle or SignalResult, has no calls, so it stays a dataclass, as in Add independent Python client generation and explicit API targets temporalio/nexgen#344.
• TypeScript isn't affected, since its JSON converter returns plain objects and the generated code builds the handle. .NET has the same round trip, since a Workflow resource decodes into a handle whose calls work. Its fix needs identity records in the .NET service contracts, so it's for a follow-up PR if this direction is OK.

Why?

A handle has calls, so decoded data shouldn't turn into one. In the Nov. 2 handles sync, we agreed that code converts a handle explicitly, as the SDK's workflow.to_stream(handle) does.

How did you test it?

Link to a test plan if any -

• Unit Tests
• Staging
• End to End Tests

The round-trip test now checks that encoding a resource raises, that decoding into the Workflow Stream raises, and that the StreamRef round-trips and gives an equal handle through the factory. The sample Workflows that returned a handle now return its identity record, and a new test checks that a SignalResult still round-trips. cargo test --all-features, cargo validate python and a full sample regeneration pass.

[moetemp]

Moved to temporalio#357.