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>

.gitignore

@@ -47,3 +47,20 @@ logs/
 
 # Claude Code
 .claude/
+
+# Django
+staticfiles/
+media/
+*.sqlite3
+db.sqlite3
+celerybeat-schedule
+celerybeat.pid
+
+# Docker
+.docker/
+
+# Database dumps
+*.sql
+
+# Keep .env.example but ignore actual .env files
+!.env.example