Batch-read and batch-write Todoist data with the v1 Sync endpoint (incremental sync, commands, temp_id)

Documented steps

1. POST https://api.todoist.com/api/v1/sync with Authorization: Bearer <token>. The body is application/x-www-form-urlencoded (NOT JSON).
2. Initial full sync: sync_token='*' plus resource_types as a JSON-encoded array of strings, e.g. ["projects","items","sections"]. Use ["all"] for everything; exclude a type by prefixing '-', e.g. "-projects".
3. Incremental sync: pass the sync_token returned by the previous response — the server returns only resources changed since then.
4. Writes: send commands as a JSON array of {type, uuid, temp_id, args}. uuid must be unique per command; temp_id is set on create commands, and later commands in the same batch may reference that temp_id directly.
5. In the response, check sync_status: each key is a command uuid mapping to "ok" or an error object like {"error_code": 15, "error": "Invalid temporary id"}; read temp_id_mapping to translate your temp_ids into real IDs.