Port upstream fixes: JSX text safety, ES2023 array methods, typo fix

Cherry-picked functional fixes from samgozman/YoptaScript upstream
(not a full merge — build tooling and package identity have diverged
too much between forks):

- core.ts: stash JSX text content before dictionary replacement and
  restore it after, so words like "return" inside JSX children no
  longer get mangled into YoptaScript keywords.
- dictionary.mjs: add ES2023 Array.prototype methods (toSorted,
  toReversed, toSpliced) that were missing from the dictionary.
- dictionary.mjs: fix 'export' translation using a Latin 'a' instead
  of Cyrillic 'а' in 'предъява'.
- docs/assets/js/converter.js: fix Tab key in the online demo
  converter inserting a literal focus-jump instead of 4 spaces.

dist/ rebuilt via `pnpm buildAll` to match.

Author: Alexey Fedorov