Fake Provider Harness + E2E Gate

Status: Delivered
CAS: CAS-3605
Delivered: 2026-05-18
PR: #968

What changed

A local-only Miniflare fake-provider harness was added for deterministic provider-plugin end-to-end tests. It runs with wrangler dev --local on port 8791, serves stable fake bank responses and a signed fake plugin catalog, and is not deployed to any Cloudflare subdomain.

Why it matters

Gives repeatable safety checks for provider-plugin behavior.
Reduces regression risk on plugin distribution/trust flow.
Keeps iOS/Desktop behavior aligned by verifying the same plugin protocol end-to-end.

Technical anchors

workers/fake-providers/
playwright.fake-providers.config.ts
docs/features/CAS-3499-declarative-cf-provider-plugins.md