Wireframe generation from workflow definitions

## Context

Part of [Epic #732](https://github.com/adobe/spectrum-design-data/issues/732) — Phase 4: Output generators and authoring app integration.

**Depends on:** #796 (authoring workflow definitions must be complete first)

## Goal

Use Claude to generate UI wireframes from the workflow definitions + spec schemas, giving the design team a concrete starting point for the authoring app. The output opens the designer conversation and informs the app architecture.

## Work needed

- [ ] For each workflow in `docs/authoring-app/workflows/`, generate annotated wireframe descriptions covering:
- Screen layout and component placement
- Data fields and their validation states
- Navigation flow between screens
- Error/success states
- [ ] Produce HTML/CSS mockups or structured descriptions a designer can translate to high-fidelity designs
- [ ] Collect designer feedback (async, via PR comments or dedicated review session)

## Notes

- The authoring app is planned as an Electron desktop app, authenticated via GitHub PAT/OAuth, authoring PRs across multiple repos
- Wireframes should reflect this context (desktop viewport, file-system-like navigation, PR workflow)
- Figma Variables PoC output (#795) may suggest additional screens (Figma sync status, export progress)

## Acceptance criteria

- Wireframe documents exist for all workflows defined in #796
- Design team has reviewed and provided feedback
- Key open questions for the architecture (see #797) are identified

Start by reading #796 and the workflow definitions in docs/authoring-app/workflows/. For each workflow, produce annotated wireframe documents or HTML/CSS mockups covering layouts, fields, navigation, and error or success states in the Electron desktop-app context. Collect design-team feedback and record the architecture questions identified during review.

Written by the indexing model from the issue text.