fix(data): populate stadium timezone in scrapers and CloudKit sync

Stadium timezones were always null because scrapers weren't passing
the timezone from STADIUM_MAPPINGS to the Stadium constructor. This
fix propagates timezone data through the entire pipeline: scrapers,
CloudKit uploader, and Swift CloudKit model.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Scripts/sportstime_parser/scrapers/nwsl.py

@@ -361,6 +361,7 @@ class NWSLScraper(BaseScraper):
                 country=info.country,
                 latitude=info.latitude,
                 longitude=info.longitude,
+                timezone=info.timezone,
                 surface="grass",
                 roof_type="open",
             )