9b8c6ba925
E15/E16: runtime store-gating bisection plus repeated-run testing show the 0x4201e210 reader-open corruption is a race (identity-independent, config alternates crash/pass), not a miscompiled TB. Blanket store-TCI suppresses it in practice. Wire ?sthash and ?stcw/stcmask/stcval opt-in debug controls.