feat: Adds support for the Todoist activity logs API endpoint

[amix]

Context

• Added getActivityLogs() method with support for:
  • Pagination (cursor-based)
  • Filtering by object type, event type, project, item, and initiator
  • Additional query parameters (since, until, annotations, etc.)
• Defined forward-compatible types for activity events (accepts unknown fields/types)
• Added validation for activity event responses
• Comprehensive test coverage for the new endpoint

API

const response = await api.getActivityLogs({
  objectType: 'item',
  eventType: 'completed',
  parentProjectId: '789',
  limit: 50,
})