(a) A lien does not extend to work, whether or not the work is authorized by a direct contractor or subcontractor, if the work is not included in a direct contract or a modification of that contract, and the claimant had actual knowledge or constructive notice of the provisions of that contract or modification before providing the work.
(b) The filing of a contract or modification of that contract with the county recorder, before the commencement of a work of improvement, is constructive notice of the provisions of the contract or modification to a person providing work on that work of improvement.