Retrieve plan provisions for a company.

Returns detailed configuration settings for the 401(k) plan associated with the company.
This includes eligibility requirements, vesting schedules, contribution settings, and other plan provisions.
Special Field Behaviors:

• exclude_highly_compensated_and_key_employees: Only available for safe harbor plans
• hours_of_service: Only populated when eligibility delay is 'Hours of Service'
• allow_permissible_withdrawal: If true, allows penalty-free withdrawal within 90 days of first auto-enrollment
• plan_cancellation_date: Uses wire_date, liquidation_date, or blackout_date in that order