Return generated model instances from connector operations

Start with the CodefulSdkGenerator and the generated connector clients described in the issue, then inspect the pinned connector contracts and the serialization/deserialization tests. Trace modeled and unmodeled response handling, including nested models, collections, optional fields, and wire-name mappings. Done means generated artifacts, API documentation, compatibility behavior, and tests match the paired AzureUX-BPM generator revision.

Problem

Generated connector clients expose response model classes, but operation methods currently deserialize JSON responses to weak dictionary types. For example, Office365Client.get_emails_async returns dict[str, Any] | None rather than an instance of its generated response model. This prevents callers and documentation from relying on typed response properties.

Identified in PR #89 review.

Proposed work

• Update the CodefulSdkGenerator to emit precise operation return annotations when the managed connector contract defines a response schema.
• Deserialize JSON responses into the corresponding generated model classes, including nested models, collections, optional fields, and wire-name mappings.
• Preserve dictionary, binary, text, and empty-response behavior when no generated response model applies.
• Regenerate affected connector clients from pinned contracts and link the paired AzureUX-BPM generator PR.
• Update API documentation after typed responses are available.

Acceptance criteria

• Connector operations with modeled response schemas return generated model instances rather than dict[str, Any].
• Return annotations distinguish modeled, unmodeled, binary, text, and no-content responses.
• Serialization/deserialization tests cover nested objects, collections, optional fields, and wire-name mappings.
• Existing connector behavior remains compatible for responses without modeled schemas.
• Generated artifacts match the paired generator revision.