After-tax payout on a Restricted Stock Unit (RSU) vest: federal ordinary income tax, state income tax, FICA (Social Security + Medicare + Additional Medicare), and the gap between mandatory 22% federal supplemental withholding and the user's marginal bracket. Use this tool for RSUs at vest; for ISO/AMT planning use `amt_iso_optimize`, for NSO use `nso_calculate`. Compares sell-at-vest vs hold-for-long-term-capital-gains (LTCG) across the chosen horizon, accounting for the 12-month short-term-vs-long-term holding threshold and the optional expected-growth assumption. Pure deterministic computation: no network access; tax tables and the 22% supplemental-withholding rate are compiled in. Returns a top-level object with keys: `vest` (vestValue, federal, state, socialSecurity, medicare, additionalMedicare, total, netCashAtVest, federalWithheldAtVest), `hold` (expectedGain at horizon, capGainFederal/State/Total including NIIT, isLongTerm), `sellNowInvest` (counterfactual: sell at vest and reinvest at expectedMarketReturn), `holdMinusSell` (dollar delta), and `bracketJump` (fromRate, toRate, thresholdAtJump on the vest amount). Example call: {shares: 1000, currentPrice: 100, ordinaryIncome: 200000, filingStatus: "single", stateCode: "CA", stillEmployed: true, holdYears: 2, volatility: 0.3, ticker: "MSFT"}. IMPORTANT: every field listed in `required` must come from the user's message OR be derivable from an optional `ticker`. The model invoking this tool MUST NOT invent a value for any required field. If the user did not supply it and no ticker resolves it, ask the user.