feat: add Django web app, CloudKit sync, dashboard, and game_datetime_utc export

Adds the full Django application layer on top of sportstime_parser:
- core: Sport, Team, Stadium, Game models with aliases and league structure
- scraper: orchestration engine, adapter, job management, Celery tasks
- cloudkit: CloudKit sync client, sync state tracking, sync jobs
- dashboard: staff dashboard for monitoring scrapers, sync, review queue
- notifications: email reports for scrape/sync results
- Docker setup for deployment (Dockerfile, docker-compose, entrypoint)

Game exports now use game_datetime_utc (ISO 8601 UTC) instead of
venue-local date+time strings, matching the canonical format used
by the iOS app.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

sportstime_parser/uploaders/diff.py

@@ -545,6 +545,7 @@ class RecordDiffer:
         - yearOpened: Year opened as int
         - imageURL: URL string for stadium image
         - sport: Sport code uppercase (e.g., "MLB")
+        - timezoneIdentifier: IANA timezone (e.g., "America/New_York")
         """
         return CloudKitRecord(
             record_name=stadium.id,
@@ -564,6 +565,7 @@ class RecordDiffer:
                 "capacity": stadium.capacity,
                 "yearOpened": stadium.opened_year,
                 "imageURL": stadium.image_url,
+                "timezoneIdentifier": stadium.timezone,
             },
         )