California’s wealthiest residents are scrambling to shield their fortunes as November comes closer with the controversial billionaire tax — with some accelerating charitable donations, buying luxury vacation homes and even joking about divorce to soften the blow. The proposed measure, if passed, would impose a one-time levy of up to 5% on the net worth of Californians worth more than $1.1 billion, based on their wealth at the end of this year if they were state residents on Jan. 1. Lower rates