Detach contacts

Removes an explicit selection of Contact associations from the configuration; the twin of \"Sync contacts\". Answers **200** the same way: `meta.status`, `meta.updated` and `meta.skipped`.\n\n**Body** (JSON):\n- `contacts` (array of Contact ids, required, 1 to 50), validated for existence only.\n\nRequires a full-access token (read-only tokens answer 403). Body validation runs before authorization: a foreign configuration with an invalid body (e.g. missing `contacts`) answers 422; only a foreign configuration with a valid body answers 404.