feat(settings,questions,school,textbooks): add brand config, question components, school dialogs, textbooks hooks

settings:

- Add actions-brand, brand-config, data-access-brand for brand management

- Add admin-file-upload-card, admin-notification-config-card, admin-school-info-card, admin-security-policy-card

- Add ai-provider-delete-dialog, ai-provider-selector, brand-config-card

- Add security-recent-logins-section, security-two-factor-section

- Add config/profile-overview-config, data-access-profile-overview, lib/system-settings-utils

questions:

- Add batch-operations, import-export-buttons, knowledge-point-selector, options-editor

- Add question-bank-results-client, question-cascade-filter, question-content-renderer, utils

school:

- Add grade-delete-dialog, grade-form-dialog, grade-list-toolbar, grade-overview-cards

- Add use-grade-data hook

textbooks:

- Add textbook-form-fields component

- Add use-kp-create, use-kp-delete, use-kp-update hooks

src/modules/settings/components/ai-provider-selector.tsx

@@ -0,0 +1,108 @@
+"use client"
+
+import { useTranslations } from "next-intl"
+import { type ReactElement } from "react"
+
+import { type AiProviderSummary } from "@/modules/settings/actions"
+import { Badge } from "@/shared/components/ui/badge"
+import { Label } from "@/shared/components/ui/label"
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from "@/shared/components/ui/select"
+
+const NEW_PROVIDER_VALUE = "__new__"
+
+interface AiProviderSelectorProps {
+  /** 已有服务商列表 */
+  providers: AiProviderSummary[]
+  /** 当前选中的服务商 ID（空字符串表示新建） */
+  selectedId: string
+  /** 当前用户 ID，用于判断是否为创建者 */
+  currentUserId?: string
+  /** 选择变更回调 */
+  onSelectChange: (value: string) => void
+}
+
+/**
+ * AI 服务商选择器
+ *
+ * 负责：
+ * - 渲染已有服务商下拉选择（含"新建"选项）
+ * - 展示当前选中服务商的密钥状态与可见性徽章
+ *
+ * 不包含任何业务逻辑，仅做展示与事件转发。
+ */
+export function AiProviderSelector({
+  providers,
+  selectedId,
+  currentUserId,
+  onSelectChange,
+}: AiProviderSelectorProps): ReactElement {
+  const t = useTranslations("settings.ai.providers")
+
+  const selectedProvider = providers.find((item) => item.id === selectedId) ?? null
+
+  const renderProviderLabel = (item: AiProviderSummary): string => {
+    const parts = [item.provider, "·", item.model]
+    if (item.isDefault) parts.push(`(${t("setDefault")})`)
+    return parts.join(" ")
+  }
+
+  const renderVisibilityBadge = (item: AiProviderSummary): ReactElement => {
+    const isOwner = currentUserId !== undefined && item.createdBy === currentUserId
+    return (
+      <span className="ml-2 inline-flex gap-1">
+        {item.visibility === "public" ? (
+          <Badge variant="secondary" className="text-[10px] px-1.5 py-0 h-4">
+            {t("badgePublic")}
+          </Badge>
+        ) : (
+          <Badge variant="outline" className="text-[10px] px-1.5 py-0 h-4">
+            {t("badgePrivate")}
+          </Badge>
+        )}
+        {isOwner ? (
+          <Badge variant="outline" className="text-[10px] px-1.5 py-0 h-4 text-muted-foreground">
+            {t("badgeOwner")}
+          </Badge>
+        ) : null}
+      </span>
+    )
+  }
+
+  return (
+    <div className="grid gap-4 sm:grid-cols-2">
+      <div className="space-y-2">
+        <Label>{t("existing")}</Label>
+        <Select value={selectedId || NEW_PROVIDER_VALUE} onValueChange={onSelectChange}>
+          <SelectTrigger>
+            <SelectValue placeholder={t("selectPlaceholder")} />
+          </SelectTrigger>
+          <SelectContent>
+            <SelectItem value={NEW_PROVIDER_VALUE}>{t("createNew")}</SelectItem>
+            {providers.map((item) => (
+              <SelectItem key={item.id} value={item.id}>
+                {renderProviderLabel(item)}
+              </SelectItem>
+            ))}
+          </SelectContent>
+        </Select>
+      </div>
+      <div className="space-y-2">
+        <Label>{t("keyStatus")}</Label>
+        <div className="flex items-center rounded-md border px-3 py-2 text-sm text-muted-foreground">
+          {selectedProvider ? renderVisibilityBadge(selectedProvider) : null}
+          <span className="ml-auto">
+            {selectedProvider?.apiKeyLast4
+              ? `${t("stored")} • ****${selectedProvider.apiKeyLast4}`
+              : t("noKey")}
+          </span>
+        </div>
+      </div>
+    </div>
+  )
+}