refactor: 重构项目结构，迁移后端至 mengyastore-backend-go，新增 Java 后端、前端功能更新及部署文档

mengyastore-backend-go/internal/handlers/admin_site.go

@@ -0,0 +1,73 @@
+package handlers
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+
+	"mengyastore-backend/internal/storage"
+)
+
+type maintenancePayload struct {
+	Maintenance bool   `json:"maintenance"`
+	Reason      string `json:"reason"`
+}
+
+func (h *AdminHandler) SetMaintenance(c *gin.Context) {
+	if !h.requireAdmin(c) {
+		return
+	}
+	var payload maintenancePayload
+	if err := c.ShouldBindJSON(&payload); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数有误"})
+		return
+	}
+	if err := h.siteStore.SetMaintenance(payload.Maintenance, payload.Reason); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{
+		"data": gin.H{
+			"maintenance": payload.Maintenance,
+			"reason":      payload.Reason,
+		},
+	})
+}
+
+func (h *AdminHandler) GetSMTPConfig(c *gin.Context) {
+	if !h.requireAdmin(c) {
+		return
+	}
+	cfg, err := h.siteStore.GetSMTPConfig()
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	// 响应中对密码脱敏处理
+	masked := cfg
+	if masked.Password != "" {
+		masked.Password = "••••••••"
+	}
+	c.JSON(http.StatusOK, gin.H{"data": masked})
+}
+
+func (h *AdminHandler) SetSMTPConfig(c *gin.Context) {
+	if !h.requireAdmin(c) {
+		return
+	}
+	var payload storage.SMTPConfig
+	if err := c.ShouldBindJSON(&payload); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数有误"})
+		return
+	}
+	// 若密码为脱敏占位符，则保留数据库中原有的密码
+	if payload.Password == "••••••••" {
+		existing, _ := h.siteStore.GetSMTPConfig()
+		payload.Password = existing.Password
+	}
+	if err := h.siteStore.SetSMTPConfig(payload); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"data": "ok"})
+}