List application metadata for an SBI and grant

Returns draft and submitted application metadata across grant versions, excluding purged applications and form answers. Does not acquire an edit lock. The SBI is obtained from the signed x-user-context token, which must contain both crn and sbi claims. Application statuses are returned unchanged; an absent status is null. The submitted date comes from application state and is null when absent. Existing POST /state creates a new application when an enabled grant is saved with a fresh reference number.