Zulip's REST API Documentation: Complete Endpoint Coverage and OpenAPI Spec Refactoring

Zulip's REST API documentation framework is well-built but incomplete, approximately 28 actionable endpoints remain undocumented, and the OpenAPI spec has accumulated structural debt through years of organic growth. This project has two phases. Phase 1 achieves complete endpoint coverage by documenting all remaining high and moderate priority endpoints following the full pipeline: OpenAPI schema, Python and cURL examples, sidebar registration, and changelog entries. Phase 2 refactors the spec's structure, promoting inline parameters to shared components, rationalising the Can*Group schema family, and cleaning up repeated inline response blocks. Deliverables: (1) Zero undocumented actionable endpoints in pending_endpoints. (2) A cleaner, more consistent OpenAPI spec with reduced duplication across parameters, schemas, and response blocks.