Support rich inline content within ProgressStep for reasoning traces #12665

Summary

ProgressStepper (in @patternfly/react-core) shows step names and statuses but isn't designed for rich content within each step. While ProgressStep accepts children (ReactNode), the layout renders children as the step title — it's not built for content blocks like reasoning text, structured data, or expandable evidence.

AI Chain of Thought patterns need a stepper-like component where each step can contain inline rich content: the reasoning text for that phase, evidence or data the AI examined, and expandable detail. A hybrid of ProgressStepper structure with ExpandableSection content within each step would address this.

popoverRender partially helps but puts content in a popover rather than inline.

Use case

A background agentic task (installation, upgrade, multi-step automation) where each phase shows not just "Analyzing logs ✓" but the actual analysis output inline — what the AI examined, what it found, and what it concluded at each step.

Context

This gap was identified during review of the Chain of Thought AI UX standard (Red Hat UXD, AUX-140). Note: ProgressStepper itself lives in patternfly/patternfly-react, but this issue is filed here since the use case is AI-driven and may be better addressed by the chatbot extension.

Jira Issue: PF-4699