feat: 添加租户成员充值功能及相关文档

backend/app/http/tenant/dto/topup_admin.go

@@ -0,0 +1,11 @@
+package dto
+
+// AdminTopupForm defines payload for tenant-admin to topup a tenant member balance.
+type AdminTopupForm struct {
+	// Amount is the topup amount in cents (CNY 分); must be > 0.
+	Amount int64 `json:"amount,omitempty"`
+	// Reason is the human-readable topup reason used for audit.
+	Reason string `json:"reason,omitempty"`
+	// IdempotencyKey ensures the topup request is processed at most once.
+	IdempotencyKey string `json:"idempotency_key,omitempty"`
+}