Add backend foundation and config-driven workbench

backend/internal/httpapi/handlers/health_handler.go

@@ -0,0 +1,21 @@
+package handlers
+
+import (
+	"net/http"
+
+	"cmr-backend/internal/httpx"
+)
+
+type HealthHandler struct{}
+
+func NewHealthHandler() *HealthHandler {
+	return &HealthHandler{}
+}
+
+func (h *HealthHandler) Get(w http.ResponseWriter, r *http.Request) {
+	httpx.WriteJSON(w, http.StatusOK, map[string]any{
+		"data": map[string]any{
+			"status": "ok",
+		},
+	})
+}