Releases json export generates org manifests

eaa4ad1: Add releases json export <org> — generate a releases.json v2 domain manifest from an already-tracked org. Reconstructs the manifest from what the registry knows about the org (products + release sources) by calling the backend GET /v1/orgs/:slug/manifest endpoint, so an owner can host the result at /.well-known/releases.json and take ownership of their listing. Prints to stdout by default (pipeable into releases json validate -) or writes to a file with -o/--output. Completes the owner round-trip alongside releases json validate. Re-ingest enriches missing fields only (fill-if-empty), never overwriting existing values.

Bumps @buildinternet/releases-api-types to ^0.41.0 for the product-level tags field, so releases json validate accepts manifests that declare product tags. json export itself trusts the backend and does not strict-validate the API response against the pinned schema (the deployed API can run ahead of the published types), so it only guards for a version: 2 shape.