California YCTC skips Form 3514 truncation, $1 minimum and whole-dollar rounding #10179

Problem

ca_yctc returns the continuous phase-out amount, but FTB Form 3514 (2025) Part VII computes the Young Child Tax Credit with truncation and a whole-dollar result (https://www.ftb.ca.gov/forms/2025/2025-3514-booklet.pdf):

• line 26: excess earned income / 100, "two decimal places, do not round"
• line 27: line 26 × $21.71, "two decimal places, do not round"
• line 28: $1,189 minus line 27; "If your credit amount is between $0 and $1, enter $1. If your credit amount is over $1, round to the nearest whole dollar."

PolicyEngine-US 2.40.1, single wage earner, one qualifying child age 3, full-year resident, 2025:

On a 239-case panel from $0 to $32,902 wages, 48 cases differ from line 28, by up to $0.62. The phase-out start, rate and end match the form; only the rounding and the $1 minimum differ. The $1 minimum is a rule, not just presentation: a filer just under the $32,901 cutoff gets $1 on the form and $0.38 here.

Should ca_yctc follow line 28 (truncate lines 26–27, $1 minimum, round to whole dollars)? If so, the same applies to the Foster Youth Tax Credit (lines 37–39).

Reproduce

from policyengine_us import Simulation
Y = 2025
for wages in [27_426, 27_500, 32_900]:
    sim = Simulation(situation={
        "people": {"a": {"age": {Y: 30}, "employment_income": {Y: wages}},
                   "c": {"age": {Y: 3}, "is_tax_unit_dependent": {Y: True}}},
        "tax_units": {"t": {"members": ["a", "c"]}},
        "households": {"h": {"members": ["a", "c"], "state_code": {Y: "CA"}}},
    })
    print(wages, sim.calculate("ca_yctc", Y)[0])  # 1188.78, 1172.72, 0.38