Export the org as a releases.json manifest

Reconstructs an owner-declared releases.json v2 domain manifest from the org's live products + sources — the inverse of the well-known materializer. Each source becomes a release locator (github/appstore/feed/url, mirroring fetch routing), nested under its product or top-level; the primary source is marked canonical. Intended as an editable baseline an owner can host at /.well-known/releases.json; the output validates against the v2 schema and round-trips through the fill-if-empty well-known sweep for enrichment. Hidden/soft-deleted entities are excluded.