George Lucas is moving forward with plans to build 224 affordable housing units on a 52-acre portion of his 1,039-acre property known as Grady Ranch, located off Lucas Valley Road near Nicasio. The filmmaker’s developer, Petaluma Ecumenical Properties, submitted a pre-application to the Marin County Community Development Agency last week that would amend the property’s 1996 Master Plan. So far the plan has met with little resistance from Lucas Valley residents, who have opposed previous…