Attachments API (core)

Routes live in decidim-restfull-core (gated at runtime by organization Toggle attachments_enabled).

Route	Notes
GET/POST /attachments	List / create
GET/PUT/DELETE /attachments/:id	Show / metadata update / delete
POST /attachments/direct_upload	ActiveStorage signed_id staging

Mode A: multipart POST /attachments — preferred for integrators.

Mode B: direct_upload + JSON POST /attachments with signed_id — large files, parity with Decidim admin.

Operations: Decidim::RestFull::Core::AttachmentsOperations (wraps Decidim::Admin::CreateAttachment / UpdateAttachment).

Integrator doc: Attachments.