- Validate OCS envelope in trash_collective, delete_collective, trash_page
- Guard _unwrap_ocs against non-OCS responses with informative OCSError
- Remove _get_ocs_headers() indirection, use class constants directly
- Split headers: _OCS_HEADERS (GET) vs _OCS_HEADERS_JSON (with body)
- Fix docstring claiming emoji param is required when it is optional
- Rename misleading test, add test for non-OCS envelope handling
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>