scripts/generate_frame_previews.py iterates figma_to_html_agent/blocks/{frame_id}/index.html,
renders preview.png via Selenium headless (capture_slide_screenshot pattern reuse), and writes
_preview_manifest.json (schema v1) with idempotent stale-detect (mtime+sha256). Build-time only
— no runtime pipeline integration, no AI calls, no MDX/Jinja regen. Stage 2 baseline (commit
56619a0): total=33, renderable=20, missing_index_html=13, orphan=1 (1171281192).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
