Create a PoC Duo Developer based on Flow registry.

Description

The original issue-to-MR was implemented as a copy / adaption of the Software engineering flow that we have for local development.

While we originally spent a lot of time on this flow, it was originally developed at a time when Sonnet 3.5 was SoTA and average SWE Bench performance of a model + tools was below 50%. Along the way we also discovered a lot of problems with the setup itself, when it comes to duplicating work or handing over the right context.

In the meantime, models became more capable and CLI coding tools established new patterns of interacting with CLIs.

There is a high risk that with the current Issue to MR we're just copying over patterns because we know them, without knowing if they actually lead to better outcomes in this new reality, while also carrying along a lot of complexity. This also requires us to develop complex components, such as gitlab-org/modelops/applied-ml/code-suggestions/ai-assist#1304 without knowing whether they are needed.

We also know that we need a flexible "duo-developer" flow to develop from an issue to an MR as well as then iterate on the MR based on user feedback.

Desired Outcome

A simple duo_developer Flow based on the tool registry., that can, immediately or in the long run replace the issue_to_mr flow.

Implementation Plan

TBD