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>

backend/internal/partners/service.go

@@ -0,0 +1,32 @@
+package partners
+
+import "context"
+
+// Service handles business logic for the partners domain.
+type Service struct {
+	repo *Repository
+}
+
+// NewService creates a new partners Service.
+func NewService(repo *Repository) *Service {
+	return &Service{repo: repo}
+}
+
+// Partner represents a participating business.
+type Partner struct {
+	ID          string `json:"id"`
+	Name        string `json:"name"`
+	Address     string `json:"address"`
+	MaxSpendPct int    `json:"max_spend_pct"`
+}
+
+// ListActive returns all partners with is_active = true.
+func (s *Service) ListActive(ctx context.Context) ([]Partner, error) {
+	return s.repo.ListActive(ctx)
+}
+
+// GetByID returns a partner by its primary key.
+// Returns ErrNotFound (from repository) if the partner does not exist.
+func (s *Service) GetByID(ctx context.Context, id string) (*Partner, error) {
+	return s.repo.GetByID(ctx, id)
+}