List Nodes

List all available node types with their input/output port schemas. Returns the static structural definition for every node type registered in the catalog — what ports each node exposes, their names, and expected data shapes — without runtime-variable values such as available languages or the TTS model catalog. This endpoint requires no `X-Workspace-Id` header and no authentication, making it suitable for static documentation generation and canvas layout tooling. For the full runtime configuration options a user would pick when wiring up a specific node (available target languages, provider/model options, voice picker URL), use `GET /api/v2/nodes/{node_type}` instead.