feat: initial commit — backend API + student cabinet frontend

- Go backend: auth (JWT), points earn/spend, QR token generation,
  partners, admin grant/stats endpoints with chi router
- Next.js 14 frontend: login, student dashboard, transaction history,
  QR display, partners list
- PostgreSQL migrations (4 tables), Redis cache, Docker Compose
- CORS middleware, role-based route protection, Zustand auth store

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

.gitignore

@@ -0,0 +1,20 @@
+# Environment — never commit real credentials
+.env
+*.env.local
+
+# Go
+backend/vendor/
+backend/coverage.out
+backend/coverage.html
+
+# Air (Go hot-reload)
+backend/tmp/
+
+# Node / Next.js
+frontend/node_modules/
+frontend/.next/
+frontend/out/
+
+# OS
+.DS_Store
+Thumbs.db