feedback7: the battle sim uses engine-independent math — Chrome, Firefox, Safari and the server agree bit for bit (PR #373 by @Cloudnyco)

- server/sim/detmath.js: hypot (sqrt of the squares, rescaled outside 2^±500), powi (integer powers in double-double,
  one rounding), sin / cos (fdlibm 5.3) and atan2 (fdlibm / FreeBSD msun) built only from correctly rounded IEEE
  operations; the sim's Math.hypot / sin / cos / atan2 / pow calls go through it (65 files); eslint.config.js forbids
  the approximated Math functions under server/sim and test/sim/detmath.test.js scans for them.
- sin / cos / atan2 are the algorithms V8 runs in Node, so the server's results stay; only hypot differs from V8's.
  Golden: 2 moved — diy-027 (a hypot distance, damage +80) and coop3-ABYSS-5 (a later card pick from round 9, same end).
- Applied unchanged after review (Grok static review: MERGE; the diff read in full: no network, no new dependency).
- Tests: broad node --test 5155 / 5155 with the new file tracked (detmath 7 / 7, package 10 / 10); lint 0 errors,
  typecheck, check:imports.

server/sim/spec.js

@@ -320,7 +320,7 @@ export function resultDigest(result) {
 const fnum = (v, d = 0) => (typeof v === 'number' && Number.isFinite(v) ? v : d);
 const cap = (list, n) => (Array.isArray(list) ? list.slice(0, n) : []);
 const isKey = (v) => typeof v === 'string' && v.length > 0 && v.length <= 64 && /^[A-Za-z0-9_\-.:]+$/.test(v);
-const uidOr = (v) => (Number.isInteger(v) && v >= 1 && v <= 2 ** 31 ? v : null);
+const uidOr = (v) => (Number.isInteger(v) && v >= 1 && v <= 0x80000000 ? v : null);
 const keyOr = (v) => (isKey(v) ? v : null);
 
 function compactMods(m) {