feat(dingtalk): 钉钉 OAuth 登录接入与 internal_only 用户属性同步

⚠️ 应用类型约束：当前实现仅支持「钉钉登录-企业内部应用」（DingTalk 开放平台
internal_app 类型）。第三方个人应用、第三方企业应用类型暂不支持——OAuth 流程
相同但 corp 校验、跨企业行为不同。backend 通过 DingTalkAppKind 校验对非
internal_app 类型 fail-closed（硬约束）。

钉钉 OAuth 登录主链
- 4 步 OAuth 链：ExchangeCodeForUserToken / GetUnionIdByUserToken /
  GetUserIdByUnionId / GetStaffInfoByUserId；app token 缓存
- pending session 机制持久化 OAuth 中间态；cookie-only token 持久化
- 三种分流：bind_login_required / email_completion / choose_account_action
- corp_restriction_policy 支持 none + internal_only；stale "whitelist" 在
  加载层与写入层均静默 coerce 为 none + slog.Warn
- bypass_registration 开关：企业内部模式豁免全局 REGISTRATION_DISABLED
- isReservedEmail / signup_source / canUnbindProvider / OAuth pending flow
  等横切点支持 dingtalk provider
- migration 136：4 表 CHECK 约束加入 'dingtalk' provider 值

internal_only 模式同步企业邮箱/姓名/部门到用户属性
- SyncCorpEmail / SyncDisplayName / SyncDept 三个独立开关 + 对应
  SyncXxxAttrKey 目标属性 key（默认 dingtalk_email / dingtalk_name /
  dingtalk_department）；非 internal_only policy 在写入层与加载层均
  coerce 为 false，admin handler 与 setting_service 双层兜底
- 同步语义：首次注册写 users.username（昵称优先 → 企业姓名 fallback），
  之后每次登录刷新 3 个属性；空值也写入以覆盖旧值
- 邮箱三级 fallback：org_email > email > extension["企业邮箱"]
  （钉钉自定义字段 JSON）
- 部门路径递归向上拼接，跳过 dept_id=1 选首个真实子部门，剥离根组织名
- GetUnionIdByUserToken 同时返回 OIDC /contact/users/me 的 nick 字段；
  新增 GetDeptInfo 调用 OAPI /topapi/v2/department/get
- AuthHandler 注入 UserAttributeService；OAuth pending flow 在
  createPendingOAuthAccount / bindPendingOAuthLogin 分别派发到
  AfterRegistration（syncUsername=true）/ AfterLogin
- migration 137 seed dingtalk_email/name/department 三个用户属性定义

附带修复（同集成路径暴露的两个 OAuth 注册回归）
- LoginOrRegisterOAuthWithTokenPair 新建用户分支用 inferLegacySignupSource
  覆写 caller 显式传入的 signupSource，导致 dingtalk/linuxdo/oidc/wechat
  渠道授权按 email 渠道读取；改为只在 caller 未显式传入时回退邮箱推断
- mergeProviderDefaultGrantSettings 把 parse fallback 默认值
  (Concurrency=5 / Balance=0) 当作"未配置"哨兵，admin 显式设 5 时被误判
  退回全局默认（复现：全局默认 1 + 渠道默认并发 5 + grant_on_signup → 新
  用户实际 concurrency=1）；去掉哨兵，admin 任何 >=0 值都覆盖 globalDefaults

前端
- DingTalk Login / Callback / EmailCompletion / ChoiceAccount / Error
  视图；router + auth API client
- admin SettingsView：corp policy radio（none / internal_only）+ bypass
  注册开关 + i18n；internal_only 下展示三同步开关 + 目标 attr key 下拉
  （拉取 user attribute definitions），展示 fieldEmail /
  qyapi_get_department_list 钉钉权限申请提示
- Profile：S1 主动绑定 / S5 解绑钉钉按钮 + 合成邮箱防自锁

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/components/user/profile/ProfileAccountBindingsCard.vue

@@ -2,6 +2,7 @@
   <ProfileIdentityBindingsSection
     :user="user"
     :linuxdo-enabled="linuxdoEnabled"
+    :dingtalk-enabled="dingtalkEnabled"
     :oidc-enabled="oidcEnabled"
     :oidc-provider-name="oidcProviderName"
     :wechat-enabled="wechatEnabled"
@@ -18,6 +19,7 @@ withDefaults(
   defineProps<{
     user: User | null
     linuxdoEnabled?: boolean
+    dingtalkEnabled?: boolean
     oidcEnabled?: boolean
     oidcProviderName?: string
     wechatEnabled?: boolean
@@ -26,6 +28,7 @@ withDefaults(
   }>(),
   {
     linuxdoEnabled: false,
+    dingtalkEnabled: false,
     oidcEnabled: false,
     oidcProviderName: 'OIDC',
     wechatEnabled: false,

frontend/src/components/user/profile/ProfileIdentityBindingsSection.vue

@@ -217,6 +217,7 @@ const props = withDefaults(
   defineProps<{
     user: User | null
     linuxdoEnabled?: boolean
+    dingtalkEnabled?: boolean
     oidcEnabled?: boolean
     oidcProviderName?: string
     wechatEnabled?: boolean
@@ -227,6 +228,7 @@ const props = withDefaults(
   }>(),
   {
     linuxdoEnabled: false,
+    dingtalkEnabled: false,
     oidcEnabled: false,
     oidcProviderName: 'OIDC',
     wechatEnabled: false,
@@ -406,6 +408,9 @@ function isProviderEnabledForBinding(provider: BindableProvider): boolean {
   if (provider === 'linuxdo') {
     return props.linuxdoEnabled
   }
+  if (provider === 'dingtalk') {
+    return props.dingtalkEnabled
+  }
   if (provider === 'oidc') {
     return props.oidcEnabled
   }
@@ -432,6 +437,17 @@ const providerItems = computed(() => [
     canUnbind: Boolean(getBindingStatus('linuxdo') && getBindingDetails('linuxdo')?.can_unbind),
     details: getBindingDetails('linuxdo'),
   },
+  {
+    provider: 'dingtalk' as const,
+    label: t('profile.authBindings.providers.dingtalk'),
+    bound: getBindingStatus('dingtalk'),
+    canBind:
+      !getBindingStatus('dingtalk') &&
+      isProviderEnabledForBinding('dingtalk') &&
+      (getBindingDetails('dingtalk')?.can_bind ?? true),
+    canUnbind: Boolean(getBindingStatus('dingtalk') && getBindingDetails('dingtalk')?.can_unbind),
+    details: getBindingDetails('dingtalk'),
+  },
   {
     provider: 'oidc' as const,
     label: t('profile.authBindings.providers.oidc', { providerName: props.oidcProviderName }),
@@ -460,6 +476,9 @@ function providerInitial(provider: UserAuthProvider): string {
   if (provider === 'linuxdo') {
     return 'L'
   }
+  if (provider === 'dingtalk') {
+    return 'D'
+  }
   if (provider === 'wechat') {
     return 'W'
   }
@@ -473,6 +492,9 @@ function providerIconClass(provider: UserAuthProvider): string {
   if (provider === 'linuxdo') {
     return 'bg-orange-100 text-orange-600 dark:bg-orange-900/20 dark:text-orange-300'
   }
+  if (provider === 'dingtalk') {
+    return 'bg-blue-100 text-blue-600 dark:bg-blue-900/20 dark:text-blue-300'
+  }
   if (provider === 'wechat') {
     return 'bg-green-100 text-green-600 dark:bg-green-900/20 dark:text-green-300'
   }

frontend/src/components/user/profile/ProfileInfoCard.vue

@@ -139,6 +139,7 @@
           <ProfileIdentityBindingsSection
             :user="user"
             :linuxdo-enabled="linuxdoEnabled"
+            :dingtalk-enabled="dingtalkEnabled"
             :oidc-enabled="oidcEnabled"
             :oidc-provider-name="oidcProviderName"
             :wechat-enabled="wechatEnabled"
@@ -190,6 +191,7 @@ import type { User, UserAuthBindingStatus, UserAuthProvider, UserProfileSourceCo
 const props = withDefaults(defineProps<{
   user: User | null
   linuxdoEnabled?: boolean
+  dingtalkEnabled?: boolean
   oidcEnabled?: boolean
   oidcProviderName?: string
   wechatEnabled?: boolean
@@ -197,6 +199,7 @@ const props = withDefaults(defineProps<{
   wechatMpEnabled?: boolean
 }>(), {
   linuxdoEnabled: false,
+  dingtalkEnabled: false,
   oidcEnabled: false,
   oidcProviderName: 'OIDC',
   wechatEnabled: false,
@@ -262,6 +265,7 @@ const memberSinceLabel = computed(() => {
 const providerLabels = computed<Record<UserAuthProvider, string>>(() => ({
   email: t('profile.authBindings.providers.email'),
   linuxdo: t('profile.authBindings.providers.linuxdo'),
+  dingtalk: t('profile.authBindings.providers.dingtalk'),
   oidc: t('profile.authBindings.providers.oidc', { providerName: props.oidcProviderName }),
   wechat: t('profile.authBindings.providers.wechat'),
   github: 'GitHub',