Proposal: extension as a primary data source (decision doc for JOY) #1175

Goal

Write a decision proposal for JOY on expanding the Rate browser extension (apps/extension) from an opt-in, quarantined crowd signal into a primary source of price and stock observations.

Background: the private crawlers in DOS/Rate-Services hit bot walls (TikTok paused in DOS/Rate-Services#658, Lazada search punish page in DOS/Rate-Services#659, Shopee works only through a logged-in runner). Comparable products (Honey, Keepa, BeeCost) are examined from public sources.

Scope (docs only)

• Docs/Proposals/2026-10-28-extension-data-source.html (Vietnamese, dark theme, for JOY)
• Docs/Proposals/2026-10-28-extension-data-source.md (short English companion)

Covers: current extension state and the /api/v1/rate/extension/ingest quarantine path; how comparable products source data; payload schema without personal data; consent UX and privacy policy; Chrome Web Store and Edge review risk; anti-poisoning; cold start; per-marketplace coverage; legal and ToS notes; why the extension client is public while verification rules stay private, with a repo ownership table; options, recommendation, milestones, metrics and open questions.

Out of scope

No change to extension behavior or the ingest API, no store publishing, no secrets, no DOS/Rate-Services edits. No scraper, proxy or captcha logic.

Done when

The proposal and companion are merged into dev after a fresh-context review, and JOY has the HTML to decide on.