Initial release: Disc Agenda frisbee tournament platform

Full-stack tournament management app with real-time scoring:
- Go 1.26 backend with REST API and WebSocket live scoring
- React 19 + Vite 8 frontend with mobile-first design
- File-based JSON storage with JSONL audit logs
- Multi-stage Docker build with Gitea CI/CD pipeline
- Post-tournament questionnaire with spirit voting
- Technical documentation and project description

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

backend/go.mod

@@ -0,0 +1,9 @@
+module github.com/frisbee-tournament/backend
+
+go 1.26
+
+require (
+	github.com/gorilla/mux v1.8.1
+	github.com/gorilla/websocket v1.5.3
+	github.com/rs/cors v1.11.0
+)