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/model/models.go

@@ -16,6 +16,8 @@ type User struct {
 	Credits          float64 `gorm:"not null;default:0"`
 	Notes            string  `gorm:"type:text"`
 	ConcurrencyGroupID string `gorm:"size:32;index"`
+	AnnouncementSeen   string `gorm:"size:32"` // version hash of the last announcement this user dismissed
+	RechargeTotal      float64 `gorm:"not null;default:0"` // 累计充值金额(元)
 	InviteCode       string  `gorm:"size:32;uniqueIndex"`
 	InvitedBy        *string `gorm:"size:32;index"`
 	InviteRewardDone bool    `gorm:"not null;default:false"`
@@ -205,9 +207,29 @@ func AutoMigrateModels() []any {
 		&SiteSetting{},
 		&StatCounter{},
 		&ConcurrencyGroup{},
+		&Order{},
 	}
 }
 
+// Order is a points-recharge order paid via 易支付 (epay). ID is our merchant
+// order number (out_trade_no). Status: pending | paid | cancelled. Unpaid orders
+// auto-cancel 30 min after creation (ExpiresAt).
+type Order struct {
+	ID          string  `gorm:"primaryKey;size:40"`
+	UserID      string  `gorm:"size:32;index;not null"`
+	Amount      float64 `gorm:"not null"`               // 充值金额(元)
+	Points      int     `gorm:"not null"`               // 到账积分
+	PayType     string  `gorm:"size:16"`                // wxpay | alipay
+	Status      string  `gorm:"size:16;index;not null"` // pending | paid | cancelled
+	TradeNo     string  `gorm:"size:64;index"`          // 易支付平台订单号
+	PayInfo     string  `gorm:"type:text"`              // 二维码 url / 跳转 url
+	PayInfoType string  `gorm:"size:16"`                // qrcode | jump | html | ...
+	ExpiresAt   time.Time `gorm:"index"`
+	PaidAt      *time.Time
+	CreatedAt   time.Time
+	UpdatedAt   time.Time
+}
+
 // ConcurrencyGroup caps how many generations a member user may run AT ONCE
 // (across their API key + 画图台). MaxConcurrency 0 = unlimited. Exactly one
 // group is IsDefault — new users are bound to it and it can't be deleted.