Critical: Add ownership checks to all order routes (IDOR fix).
High: Redis rate limiting on auth endpoints, HMAC-signed internal
service calls replacing header-presence-only checks, nh3 HTML
sanitization on ghost_sync and product import, internal auth on
market API endpoints, SHA-256 hashed OAuth grant/code tokens.
Medium: SECRET_KEY production guard, AP signature enforcement,
is_admin param removal, cart_sid validation, SSRF protection on
remote actor fetch.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Unhandled exceptions in action handlers were returned as opaque
400/500 by Quart's default error handler. Now we catch, log the
full traceback, and return a JSON error body with 500 status so
the caller gets useful diagnostics.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>