Store feeds

GET|POST /api/v1/projects/{project_ref}/store/{protocol}/{listing_slug}
optional /{doc}.

Protocols: sparkle, electron, tauri, squirrel, clickonce, appimage, winget, msix, fdroid. Missing listing, unknown protocol, or a slug-less legacy path → plaintext 404 (no JSON code). Official SDKs do not read feeds.

Contract: API reference (openapi.client.json; open Scalar). Listing CRUD stays on the admin reference. Scenarios: Electron, Sparkle.