Transform MRs from manual tasks to an automated workflow

What this post added

Introduces significant enhancements to GitLab's Developer Flow, extending its automation capabilities across the entire MR lifecycle. Key new features include an AI agent that can address reviewer feedback, resolve merge conflicts autonomously ('Resolve with Duo'), research codebases, split large MRs, and implement features. It also adds a one-click rebase and merge functionality. The underlying architecture is now a single agentic loop with a full developer toolset, leveraging project setup files for context.