feat: 易支付积分充值 + 站内公告 + OpenAI 视频修复 + grok/adobe 失败处理

充值/订单(易支付 mapi):
- 订单表 + 30 分钟自动取消;支付弹窗(二维码/跳转监控、倒计时、轮询、5s 倒计时关闭)
- 系统设置可配:开关/商户ID/密钥/支付地址(根地址拼 /mapi)/支付方式/最低额/积分比例(默认 1元=100积分)
- 异步通知 MD5 验签、幂等到账;用户累计充值;前台/后台订单页(筛选+搜索+分页,前后台分风格);用户管理累计充值列

站内公告:
- Markdown 公告,登录用户首次访问/刷新弹出;内容哈希做版本,改了就重新推;管理员不弹;空内容=下线

OpenAI 视频(/v1/videos)修复:
- /content 拿不到视频:grok 资源 URL 需鉴权,改为用生成账号 token 取流;adobe/runway 公开 URL 直代理(不存 RustFS)
- size→分辨率用短边判定(1280x720 = 720p,之前误判 1080p 被拒)

失败处理:
- grok 429「Too many requests」/403 anti-bot 改判临时错误(不再误封号),真额度耗尽才算 quota
- adobe 视频 408 / system under load 归为临时错误 → tempAsDead 封号

其它:
- 充值默认关闭;签到格子浅色可见;登录验证码按钮浅色可读;并发/账户信息展示
- 创作记录/画图台只显示画图台作品(排除 API);日志页 API 视频预览显示 —
- 视频去画中画/下载/投屏(全局);图片缩略图改背景图规避 Edge 视觉搜索
- 订单/兑换码/配置/日志菜单文案与图标;充值版块样式

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/internal/repo/order_repo.go

@@ -0,0 +1,83 @@
+package repo
+
+import (
+	"context"
+	"time"
+
+	"backend/internal/model"
+	"gorm.io/gorm"
+)
+
+type OrderRepository struct{ db *gorm.DB }
+
+func NewOrderRepository(db *gorm.DB) *OrderRepository { return &OrderRepository{db: db} }
+
+func (r *OrderRepository) Create(ctx context.Context, o *model.Order) error {
+	return r.db.WithContext(ctx).Create(o).Error
+}
+
+func (r *OrderRepository) Get(ctx context.Context, id string) (*model.Order, error) {
+	var o model.Order
+	if err := r.db.WithContext(ctx).Where("id = ?", id).First(&o).Error; err != nil {
+		return nil, err
+	}
+	return &o, nil
+}
+
+func (r *OrderRepository) Update(ctx context.Context, id string, patch map[string]any) error {
+	return r.db.WithContext(ctx).Model(&model.Order{}).Where("id = ?", id).Updates(patch).Error
+}
+
+// ListByUser returns a user's own orders, newest first, with pagination + total.
+func (r *OrderRepository) ListByUser(ctx context.Context, userID, status string, limit, offset int) ([]model.Order, int64, error) {
+	var out []model.Order
+	var total int64
+	q := r.db.WithContext(ctx).Model(&model.Order{}).Where("user_id = ?", userID)
+	if status != "" {
+		q = q.Where("status = ?", status)
+	}
+	if err := q.Count(&total).Error; err != nil {
+		return nil, 0, err
+	}
+	if limit <= 0 {
+		limit = 20
+	}
+	err := q.Order("created_at desc").Limit(limit).Offset(offset).Find(&out).Error
+	return out, total, err
+}
+
+// List returns all orders (admin) with optional status filter + pagination.
+func (r *OrderRepository) List(ctx context.Context, status string, limit, offset int) ([]model.Order, int64, error) {
+	var out []model.Order
+	var total int64
+	q := r.db.WithContext(ctx).Model(&model.Order{})
+	if status != "" {
+		q = q.Where("status = ?", status)
+	}
+	if err := q.Count(&total).Error; err != nil {
+		return nil, 0, err
+	}
+	if limit <= 0 {
+		limit = 50
+	}
+	err := q.Order("created_at desc").Limit(limit).Offset(offset).Find(&out).Error
+	return out, total, err
+}
+
+// MarkPaid flips a pending order to paid atomically. Returns true only on the
+// transition pending→paid, so a duplicate notify can never double-credit.
+func (r *OrderRepository) MarkPaid(ctx context.Context, id, tradeNo string, paidAt time.Time) (bool, error) {
+	res := r.db.WithContext(ctx).Model(&model.Order{}).
+		Where("id = ? AND status = ?", id, "pending").
+		Updates(map[string]any{"status": "paid", "paid_at": paidAt, "trade_no": tradeNo})
+	return res.RowsAffected > 0, res.Error
+}
+
+// ExpirePending cancels every still-pending order whose ExpiresAt has passed and
+// returns how many it cancelled.
+func (r *OrderRepository) ExpirePending(ctx context.Context, now time.Time) (int64, error) {
+	res := r.db.WithContext(ctx).Model(&model.Order{}).
+		Where("status = ? AND expires_at < ?", "pending", now).
+		Updates(map[string]any{"status": "cancelled"})
+	return res.RowsAffected, res.Error
+}