Capital gain distributions on activities and corporate actions

Broker API

Adds capital gain distribution detail to account activities.

• New CGDActivityV2 payload for CGD activities on the activity event endpoints.
• The ActivitySubType schema now documents CGD sub-types: LTCG (Long-Term Capital Gain) and STCG (Short-Term Capital Gain).
• The ActivityType description clarifies CGD as Capital Gains Distribution.

Affected Endpoints

• GET /v1/accounts/activities
• GET /v1/accounts/activities/{activity_type}
• GET /v2beta1/accounts/{account_id}/events/activities/{event_id}
• GET /v2beta1/events/activities

Market Data API

Adds capital_gains_distribution as a corporate action type.

• The types query parameter on the corporate actions endpoint accepts capital_gains_distribution, and responses include a capital_gains_distributions array.
• The corporate actions SSE stream adds the capital_gains_distribution_corporateaction_event value on event_type, with a matching ca payload schema.

Affected Endpoints

• GET /v1/corporate-actions
• GET /v1beta1/events/corporate-actions