Add Streaming Support to AI Workflows

[monsieurBoutte]

Add Streaming Support to AI Workflows

Summary

We currently only support fully buffered generate style responses for AI workflows. For improved UX and faster time-to-first-token, we should explore adding client-side streaming support where appropriate.

Problem

Some workflows can take multiple seconds to complete end-to-end. For peak UX, users should not have to wait for the full response before seeing progress.

Proposed Direction

• Introduce an option to choose between:
  • generate (fully buffered)
  • stream (incremental tokens)
• Use inferred conditional types so return types are correctly narrowed based on the selected mode.
• Evaluate which existing workflows are safe and valuable to support streaming.

Success Criteria

• At least one workflow successfully supports streaming end-to-end.
• Clean, type-safe developer API.
• No breaking changes to existing generate consumers.