Deletes an estimate by its Estimate ID.

Only estimates with a status of Draft, Sent, Accepted or Rejected can be deleted. Estimates that have been converted to an invoice are protected and return 422. The estimate's line items and activity records are removed with it; file attachments are flagged for asynchronous removal from storage. A repeat DELETE of the same ID returns 404, so automation retry loops are safe.

Example request: DELETE /api/Estimate?EstimateID=4120 Example response (200): { "estimateID": 4120, "isDeleted": true }