✨ feat(models-sync): official upstream sync with conflict resolution UI, opt‑out flag, and backend resiliency

Backend
- Add endpoints:
  - GET /api/models/sync_upstream/preview — diff preview (filters out models with sync_official = 0)
  - POST /api/models/sync_upstream — apply sync (create missing; optionally overwrite selected fields)
- Respect opt‑out: skip models with sync_official = 0 in both preview and apply
- Return detailed stats: created_models, created_vendors, updated_models, skipped_models, plus created_list / updated_list
- Add model.Model.SyncOfficial (default 1); auto‑migrated by GORM
- Make HTTP fetching robust:
  - Shared http.Client (connection reuse) with 3x exponential backoff retry
  - 10MB response cap; keep existing IPv4‑first for *.github.io
- Vendor handling:
  - New ensureVendorID helper (cache lookup → DB lookup → create), reduces round‑trips
  - Transactional overwrite to avoid partial updates
- Small cleanups and clearer helpers (containsField, coalesce, chooseStatus)

Frontend
- ModelsActions: add “Sync official” button with Popover (p‑2) explaining community contribution; loading = syncing || previewing; preview → conflict modal → apply flow
- New UpstreamConflictModal:
  - Per‑field columns (description/icon/tags/vendor/name_rule/status) with column‑level checkbox to select all
  - Cell with Checkbox + Tag (“Click to view differences”) and Popover (p‑2) showing Local vs Official values
  - Auto‑hide columns with no conflicts; responsive width; use native Semi Modal footer
  - Full i18n coverage
- useModelsData: add syncing/previewing states; new methods previewUpstreamDiff, applyUpstreamOverwrite, syncUpstream; refresh vendors/models after apply
- EditModelModal: add “Participate in official sync” switch; persisted as sync_official
- ModelsColumnDefs: add “Participate in official sync” column

i18n
- Add missing English keys for the new UI and messages; fix quoting issues

Refs
- Upstream metadata: https://github.com/basellm/llm-metadata

web/src/i18n/locales/en.json

@@ -1,6 +1,5 @@
 {
   "主页": "Home",
-  "文档": "Docs",
   "控制台": "Console",
   "$%.6f 额度": "$%.6f quota",
   "或": "or",
@@ -165,7 +164,6 @@
   "出现错误，第 ${count} 次重试中...": "Error occurred, retry attempt ${count}...",
   "首页": "Home",
   "渠道": "Channel",
-  "渠道管理": "Channels",
   "令牌": "Tokens",
   "兑换额度": "Redeem",
   "充值": "Recharge",
@@ -174,7 +172,6 @@
   "设置": "Settings",
   "关于": "About",
   "价格": "Pricing",
-  "聊天": "Chat",
   "注销成功!": "Logout successful!",
   "注销": "Logout",
   "登录": "Sign in",
@@ -443,9 +440,7 @@
   "兑换码": "Redeem Code",
   "管理用户": "Manage Users",
   "额度明细": "Quota Details",
-  "个人设置": "Personal Settings",
   "运营设置": "Operation Settings",
-  "系统设置": "System Settings",
   "其他设置": "Other Settings",
   "项目仓库地址": "Project Repository Address",
   "可在设置页面设置关于内容，支持 HTML & Markdown": "The About content can be set on the settings page, supporting HTML & Markdown",
@@ -585,10 +580,7 @@
   "确定是否要修复数据库一致性？": "Are you sure you want to repair database consistency?",
   "进行该操作时，可能导致渠道访问错误，请仅在数据库出现问题时使用": "When performing this operation, it may cause channel access errors. Please only use it when there is a problem with the database.",
   "当前没有可用的启用令牌，请确认是否有令牌处于启用状态！": "There are currently no enablement tokens available, please confirm if one is enabled!",
-  "令牌管理": "API Keys",
-  "使用日志": "Usage log",
   "Midjourney日志": "Midjourney",
-  "数据看板": "Dashboard",
   "模型列表": "Model list",
   "常见问题": "FAQ",
   "免费体验": "Free trial",
@@ -628,7 +620,6 @@
   "重置成功": "Reset successful",
   "加载数据出错:": "Error loading data:",
   "加载数据时发生错误: ": "An error occurred while loading data:",
-  "保存成功": "Saved successfully",
   "部分保存失败，请重试": "Partial saving failed, please try again",
   "请检查输入": "Please check your input",
   "如何区分不同分组不同模型的价格：供参考的配置方式": "How to distinguish the prices of different models in different groups: configuration method for reference",
@@ -653,7 +644,6 @@
   "窗口等待": "window wait",
   "失败": "Failed",
   "绘图": "Drawing",
-  "绘图日志": "Drawing log",
   "放大": "Upscalers",
   "微妙放大": "Upscale (Subtle)",
   "创造放大": "Upscale (Creative)",
@@ -793,7 +783,6 @@
   "邮箱": "Email",
   "已有账户？": "Already have an account?",
   "创意任务": "Tasks",
-  "用户管理": "User Management",
   "任务ID（点击查看详情）": "Task ID (click to view details)",
   "进度": "schedule",
   "花费时间": "spend time",
@@ -943,7 +932,6 @@
   "不是合法的 JSON 字符串": "Not a valid JSON string",
   "个人中心": "Personal center",
   "代理商": "Agent",
-  "钱包管理": "Wallet",
   "备注": "Remark",
   "工作台": "Workbench",
   "已复制：": "Copied:",
@@ -957,7 +945,6 @@
   "黑夜模式": "Dark mode",
   "管理员设置": "Admin",
   "待更新": "To be updated",
-  "模型广场": "Pricing",
   "支付中..": "Paying",
   "查看图片": "View pictures",
   "并发限制": "Concurrency limit",
@@ -1043,7 +1030,6 @@
   "在iframe中加载": "Load in iframe",
   "补全倍率": "Completion ratio",
   "保存分组数据失败": "Failed to save group data",
-  "保存失败，请重试": "Save failed, please try again",
   "没有可用的使用信息": "No usage information available",
   "使用详情": "Usage details",
   "收起": "Collapse",
@@ -1187,7 +1173,6 @@
   "知识库 ID": "Knowledge Base ID",
   "请输入知识库 ID，例如：123456": "Please enter knowledge base ID, e.g.: 123456",
   "可选值": "Optional value",
-  "任务日志": "Task log",
   "你好": "Hello",
   "你好，请问有什么可以帮助您的吗？": "Hello, how may I help you?",
   "用户分组": "Your default group",
@@ -1329,7 +1314,6 @@
   "当剩余额度低于此数值时，系统将通过选择的方式发送通知": "When the remaining quota is lower than this value, the system will send a notification through the selected method",
   "Webhook请求结构": "Webhook request structure",
   "只支持https，系统将以 POST 方式发送通知，请确保地址可以接收 POST 请求": "Only https is supported, the system will send a notification through POST, please ensure the address can receive POST requests",
-  "保存设置": "Save settings",
   "通知邮箱": "Notification email",
   "设置用于接收额度预警的邮箱地址，不填则使用账号绑定的邮箱": "Set the email address for receiving quota warning notifications, if not set, the email address bound to the account will be used",
   "留空则使用账号绑定的邮箱": "If left blank, the email address bound to the account will be used",
@@ -1501,7 +1485,6 @@
   "收益": "Earnings",
   "无邀请人": "No Inviter",
   "邀请人": "Inviter",
-  "兑换码管理": "Redemption Code",
   "设置兑换码的基本信息": "Set redemption code basic information",
   "设置兑换码的额度和数量": "Set redemption code quota and quantity",
   "编辑用户": "Edit User",
@@ -1595,7 +1578,6 @@
   "加载中...": "Loading...",
   "正在跳转...": "Redirecting...",
   "暂无公告": "No Notice",
-  "操练场": "Playground",
   "欢迎使用，请完成以下设置以开始使用系统": "Welcome to use, please complete the following settings to start using the system",
   "数据库检查": "Database Check",
   "验证数据库连接状态": "Verify database connection status",
@@ -1811,7 +1793,6 @@
   "系统提示覆盖": "System prompt override",
   "模型: {{ratio}}": "Model: {{ratio}}",
   "专属倍率": "Exclusive group ratio",
-  "模型管理": "Models",
   "匹配类型": "Matching type",
   "描述": "Description",
   "供应商": "Vendor",
@@ -2075,5 +2056,18 @@
   "保存边栏设置": "Save Sidebar Settings",
   "侧边栏设置保存成功": "Sidebar settings saved successfully",
   "需要登录访问": "Require Login",
-  "开启后未登录用户无法访问模型广场": "When enabled, unauthenticated users cannot access the model marketplace"
+  "开启后未登录用户无法访问模型广场": "When enabled, unauthenticated users cannot access the model marketplace",
+  "同步官方": "Sync official",
+  "参与官方同步": "Participate in official sync",
+  "关闭后，此模型将不会被“同步官方”自动覆盖或创建": "When turned off, this model will be skipped by Sync official (no auto create/overwrite)",
+  "选择要覆盖的冲突项": "Select conflict items to overwrite",
+  "点击查看差异": "Click to view differences",
+  "无冲突项": "No conflict items",
+  "应用覆盖": "Apply overwrite",
+  "仅会覆盖你勾选的字段，未勾选的字段保持本地不变。": "Only selected fields will be overwritten; unselected fields remain unchanged.",
+  "本地": "Local",
+  "官方": "Official",
+  "模型社区需要大家的共同维护，如发现数据有误或想贡献新的模型数据，请访问：": "The model community needs everyone's contribution. If you find incorrect data or want to contribute new models, please visit:",
+  "是": "Yes",
+  "否": "No"
 }