Transitioning to native JavaScript timezone APIs in CPTimeZone exposed latent defects in CPDateFormatter's token parsing and offset generation.
* Update CPDateFormatterTest to enforce strict UTC temporal baseline matching.
* Bypass unreliable host JavaScript local string parsing heuristics in `_dateFromTokens:dateComponents:` by implementing native `Date.UTC()` absolute timestamp construction.
* Fix GMT offset string generation for the `Z` token to correctly evaluate zero-offset timezones as positive, ensuring standard `+0000` formatting instead of `-0000`.
David Richardson
6adb410cc6