Goals API: dueDate added to key results

Key results in the Goals API now have an optional dueDate field (YYYY-MM-DD).

• Create and update key results: you can set dueDate. If it’s omitted on create, it defaults to the goal’s due date.
• Search and metadata: dueDate is returned in key result search results and listed in the key results metadata.

No changes are needed for existing integrations.

See the Goals API reference for details.