VendorState sits beside ExternalContainerState (contract decision 1)
with the same shape: private setters, Changed event, Reset with
AggregateException fanout; domain-shaped like ContainerContentEntry
since Core cannot reference Core.Net. No Runtime wiring, no UI — 5.3's
job.
VendorPricing ports ShopSystem::BuyPrice/SellPrice (0x006B6120/
0x006B6180) faithfully: retail's literal three-way branch survives,
including the unreachable-with-real-data negative -1 sentinel that
ACE's Math.Max(1, ...) collapse erases — equivalence for legitimate
inputs is hand-proven and documented rather than silently assumed.
Seven conformance tests with hand-derived golden values (float32
semantics verified independently), covering rate=1.0, fractional
rates, value=0, the rounding-sensitive halfway case, stack
multipliers, the ItemType rate-override branch, and the sentinel.
Clean-room complete solution with 5.1+5.2 in place: 11,291 passed /
4 skipped / 0 failed.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
