Partially updates deposit_configs.overrides and deposit_configs.interest_capitalization_mode on an active deposit account attachment. Each field is processed using three‑state PATCH semantics, allowing values to be added, changed, or cleared as part of the update.

• Omitted: Keeps the current value
• null: Removes the override; falls back through the cascade (program → product)
• Value: Replaces the current override with the supplied value

NOTES:

• At least one of deposit_configs.overrides or deposit_configs.interest_capitalization_mode must be provided.
• The overrides envelope, if provided, must contain at least one field. Sending an empty object returns 400 EIBACC0315.
• renewal_term still requires ROLLOVER configured in maturity_instructions somewhere in the fallback sequence (400 EIBACC0310 otherwise).

This endpoint generates an Account attachment updated event.