FX.109 Accuracy: exact-equality comparisons reviewed, 7 given a tolerance, the rest tagged (new Changes tab)

Prompted by a community comment that floating-point == / === comparisons in the apps look suspect. All 367 candidates on /accuracy/comparisons were read. 7 now compare within a tolerance (1e-9 relative): electrical add-on (2 places), process dispersion, process vessel, PartCraft lattice, PDF rectangle corners (isAxisRect), window cut-list part merge. The other 277 were left exact on purpose (whole numbers, copied values, zero guards, typed codes, triangulation and ordering tie-breaks) and tagged with the reason in plain words. Every change is on /accuracy/changes with before, after, UTC time and a revert command (node tools/accuracy-equality/fix.mjs revert EQ-n). a Discord member (/lab) only. Not done: live shared shell (engines/risk/weibull.js, calc.js:240) waits for a release go; 6 needs-review items (EQ-0094, 0209, 0215, 0248, 0273, 0279) still to decide; app suites not re-run, edited files only checked to parse; reviewers' reasons come from reading code, not running it.