nx_sudoku_core.nx

nx_sudoku_core.nx -- LIB (no main): the ONE sudoku algorithm in the estate, written BASE-RELATIVE so the identical code runs natively (base = an mmap'd buffer) and inside our WebAssembly (base = 0). WHY BASE-RELATIVE. The estate's wasm game contract (nx_wasm_2048, nx_wasm_craft) is that a game is pure integer logic over a flat memory image addressed as base+offset. A module written that way needs no allocator, no syscalls and no host cooperation, so the SAME source is the native binary AND the browser module. The alternative -- one copy in NishiLang for the tool and another in JavaScript for the page -- is two implementations of one ruleset, which is the duplicate-ruler defect the estate keeps paying for. There is exactly ONE solver, ONE counter and ONE carver here, and both consumers (nx_sudoku for banks, nx_sudoku_wasm for play) compose them. THE LOAD-BEARING PROPERTY: uniqueness is COUNTED, never assumed. sc_carve empties a cell only when sc_count still returns exactly 1, and sc_count saturates at 2 because "is it still unique" only ever needs to separate 1 from more-than-1. The clue floor is 17 -- McGuire, Tugemann & Civario (2012) proved exhaustively that no 16-clue sudoku has a unique solution, so a request for fewer is CLAMPED rather than honoured: asking for 16 asks for something that provably does not exist. Deterministic: the PRNG is a seeded LCG held in the memory image, so a given seed reproduces a given puzzle exactly. A generator you cannot re-run is not one you can test. license_tier: ORIGINAL No hw writes (Rule 26).