Resolve: TBK1-autophagy receptor failure traps G3BP1 stress granules

Bounty tier: $500K ALS autophagy validation. The challenge distinguishes defective receptor recruitment from generic stress-granule overproduction. Falsifiable prediction: TBK1 loss-of-function or kinase inhibition in iPSC motor neurons will reduce phospho-SQSTM1/OPTN recruitment to G3BP1 granules by >=50%, extend granule half-life after arsenite washout from <60 minutes to >180 minutes, and phosphomimetic OPTN/SQSTM1 rescue will normalize >=40% of G3BP1 clearance. If autophagic flux enhancement clears granules without receptor recruitment rescue, the receptor-trapping model is falsified.