第 0 阶段：项目初始化

backend/internal/handler/health.go

@@ -0,0 +1,24 @@
+package handler
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/gin-gonic/gin"
+)
+
+type HealthHandler struct {
+	startedAt time.Time
+}
+
+func NewHealthHandler() *HealthHandler {
+	return &HealthHandler{startedAt: time.Now()}
+}
+
+func (h *HealthHandler) Check(c *gin.Context) {
+	c.JSON(http.StatusOK, gin.H{
+		"status":     "ok",
+		"service":    "hfb-api",
+		"started_at": h.startedAt.Format(time.RFC3339),
+	})
+}