nx_sudoku.nx

nx_sudoku.nx -- the FILE SURFACE for sudoku: proven-unique puzzle banks in the estate's own format. THIS FILE HOLDS NO ALGORITHM. Rules, solver, solution counter and carver live in nx_sudoku_core.nx and are shared with nx_sudoku_wasm (the playable module). An earlier version of this file carried its own sd_ok/sd_fill/sd_count/sd_carve, which meant TWO implementations of one ruleset in the estate -- the duplicate-ruler defect. The extraction was only half the fix; deleting this copy is the rest. Verified by re-banking seed 1101 and comparing bytes: a refactor that reproduces the banked artifact exactly has provably changed no behaviour. NATIVE BANK FORMAT. The bank is a sovereign nx_gamesave state file, NOT a TSV. TSV has no header, no version, no checksum and no atomicity: a torn write or a flipped byte reads back as a plausible puzzle. gs_save gives the estate's guarantees for free -- 48-byte versioned header, rolling checksum with CORRUPTION REFUSED LOUD, a future format REFUSED rather than misparsed, atomic tmp+fsync+rename, and additive .prev banking (rule 13). layout: 162 i64 per puzzle -- [0..80] the puzzle digits, [81..161] its solution. UNIQUENESS IS COUNTED, NEVER ASSUMED: a clue is removed only while exactly one solution survives, and every row is re-counted before it reaches the file. The clue floor is 17 -- McGuire, Tugemann & Civario (2012) proved no 16-clue sudoku has a unique solution, so fewer is CLAMPED, not honoured. usage: nx_sudoku --kat self-test -> VERDICT=GREEN/RED, exit carries it nx_sudoku bank <count> <clues> <seed> <out.sav> the native, checksummed bank nx_sudoku jsbank <in.sav> <out.js> derive the page fragment FROM that bank nx_sudoku gen <count> <clues> <seed> text emit, for eyeballing a grid exit : 0 ok | 1 RED/refused | 2 usage license_tier: ORIGINAL expect_exit: 0