US state income-tax answers grounded in the actual state code with machine-verified citations a CPA can check. California (R&TC/FTB/OTA, static two-era conformity, NOL suspension) and New York (Tax Law/20 NYCRR/DTF/Tribunal, rolling conformity + OBBBA decoupling, convenience rule, statutory residency, resident-credit trap). Citation-locked state tax intelligence, not advice. More states as corpora ship.