Spike 3 — Extract + jump-back

Goal

Prototype main-content extract with stable sourceBlockId and Side Panel → content script jump + highlight.

How to run

  1. Open a normal article / GitHub README
  2. Labs → Spike Extract (or Summarize and click a source)

Expected observations

  • Structured blocks with locator + fingerprint
  • Clicking citation scrolls and briefly highlights
  • Protected pages return PAGE_PROTECTED

Decision

Ship Readability + DOM block mapping. SPA low-quality extracts prompt selection fallback.