v1.4.0 — Reliability & correctness improvements

Fixed timezone spoofing for regions that don't observe DST (e.g. Asia/Tokyo, America/Phoenix). Offsets are now resolved using the browser's Intl API instead of heuristics.
Fixed a race condition where geolocation overrides could be installed after page scripts had already run, briefly exposing your real location.
Fixed async message handling to use Firefox's native Promise-based pattern, improving reliability of settings delivery between components.
Internal settings like your GeoNames username are no longer sent to content scripts — only the fields needed for spoofing are broadcast.
Build system now automatically syncs the version between package.json and manifest.json.