- relay: SSE stream error exposure improvements (Claude/Gemini/OpenAI)
- test: add mock capture server for E2E relay capture testing

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

- Gemini stream: 捕获 promptFeedback.blockReason 后停止流并返回 OpenAPI 错误
- OpenAI stream: 检测 SSE 帧中的 error 响应，在首帧写入前转换为 API 错误
- Responses stream: 处理 response.error / response.failed / error 类型帧
- 新增 ClearEventStreamHeadersIfNotWritten 工具方法，错误转换时清除流式头
- 新增 streamOpenAIErrorFromData，从 SSE data 帧提取 OpenAPI 错误结构
- 上游错误体会截断后存入 UpstreamBody 供排障

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

Co-Authored-By: Codex <noreply@anthropic.com>

Co-Authored-By: Codex <noreply@anthropic.com>

Co-Authored-By: Codex <noreply@anthropic.com>

Co-Authored-By: Codex <noreply@anthropic.com>

Co-Authored-By: Codex <noreply@anthropic.com>

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

- 前端冲突处理页面禁用 cn_already_synced_to_ov 场景的 merge 操作
- 后端 resolve 接口拒绝将已存在 synced copy 的 CN 用户作为 merge 目标
- 补充对应控制器测试

Co-Authored-By: Codex <noreply@anthropic.com>

- 为 user-migrations 管理路由增加仅 master 节点可访问的保护
- 为导入创建用户补充用户名、显示名、邮箱长度校验及测试
- 调整测试环境部署脚本，自动写入 CN/OV 的 NODE_TYPE

Co-Authored-By: Codex <noreply@anthropic.com>

# Conflicts:
#	controller/user.go
#	web/src/i18n/locales/en.json
#	web/src/i18n/locales/zh-CN.json

Add candidate user selection and explicit_ids batch creation flow for overseas migration. Also add cancellable batches to release selected-user locks and extend backend, frontend, and e2e coverage for the new flow.

Co-Authored-By: Codex <noreply@anthropic.com>

Co-Authored-By: Codex <noreply@anthropic.com>

格式：{时间}-{分支}-{短commit}[-dirty]
示例：202606051500-master-e9d5d51b（干净）
      202606051500-master-e9d5d51b-dirty（有未提交改动）

前端对同步用户用 SyncedQuota 替代 Quota 展示，但后端比较时
用的是数据库真实 Quota 字段，导致两者不同而触发拦截。
改为比较 SyncedQuota，只有真正修改额度时才拦截。

- 将操作列「高级比例」按钮改为编辑图标按钮，打开完整编辑弹窗
- 编辑弹窗新增定价模式切换（按量计费/按次计费）
- 按量计费下支持按倍率设置和按价格设置两种子模式
- 按倍率：模型倍率、补全倍率
- 按价格：输入价格、输出价格（$/1M tokens），自动计算倍率
- 高级比例区域：缓存读取、缓存创建、图片、音频输入、音频输出
- 修复 SubmitData 遗漏高级倍率字段保存的 bug（CacheRatio 等 5 个字段）
- 清理死代码（未调用的转换函数、残留 console.log）

- Remove advanced ratio columns from the table
- Add 'advanced ratios' button in action column
- Add edit modal with Form.InputNumber fields (same as visual editor)
- Table stays clean, advanced settings only visible on click

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

- Add cache/image/audio ratio columns to the table
- Add advanced ratio fields to the add model modal
- Update data init, submit, and addModel to handle new fields
- Use formRef to read InputNumber values (same fix as visual editor)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

- Replace || with ?? in addOrUpdateModel to keep 0 values (0 || '' = '')
- Add null check in SubmitData to avoid writing undefined
- Fix formRef value reading to preserve 0 vs empty distinction

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Form.InputNumber values were not synced to currentModel state via
onChange, so the advanced ratio fields were always empty when saving.
Now reads values directly from formRef in onOk handler.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>