feat(admin-brand): add question expansion service and related functionality

- Implemented QuestionExpansionService for generating and materializing questions based on combinations and AI distillation.
- Added question metadata classification logic to infer intent and layer of questions.
- Created API handlers for question expansion operations including combination preview, AI distillation, metadata classification, and materialization.
- Introduced database migrations to support new question-related fields and constraints in brand_questions and brand_keywords tables.
- Added caching mechanism for AI distillation results to improve performance.
- Defined JSON schemas for question distillation responses to ensure data integrity.

apps/admin-web/src/lib/api.ts

@@ -72,6 +72,8 @@ import type {
   ListDesktopPublishTasksParams,
   LoginRequest,
   LoginResponse,
+  MaterializeQuestionsRequest,
+  MaterializeQuestionsResult,
   MediaPlatform,
   MonitoringCitationSummaryResponse,
   MonitoringCollectNowResponse,
@@ -89,6 +91,9 @@ import type {
   PublishKolPromptRequest,
   PublishRecord,
   Question,
+  QuestionCandidateResult,
+  QuestionCombinationRequest,
+  QuestionDistillRequest,
   QuestionRequest,
   QuotaSummary,
   RecentArticle,
@@ -122,6 +127,8 @@ import type {
   UpdateQuestionRequest,
   UserInfo,
   WorkspaceOverview,
+  ClassifyQuestionsRequest,
+  ClassifiedQuestion,
 } from '@geo/shared-types'
 
 import {
@@ -1036,6 +1043,30 @@ export const brandsApi = {
       params: keywordId ? { keyword_id: keywordId } : undefined,
     })
   },
+  previewQuestionCombination(brandId: number, payload: QuestionCombinationRequest) {
+    return apiClient.post<QuestionCandidateResult, QuestionCombinationRequest>(
+      `/api/tenant/brands/${brandId}/questions/combination-preview`,
+      payload,
+    )
+  },
+  distillQuestions(brandId: number, payload: QuestionDistillRequest) {
+    return apiClient.post<QuestionCandidateResult, QuestionDistillRequest>(
+      `/api/tenant/brands/${brandId}/questions/ai-distill`,
+      payload,
+    )
+  },
+  classifyQuestions(brandId: number, payload: ClassifyQuestionsRequest) {
+    return apiClient.post<ClassifiedQuestion[], ClassifyQuestionsRequest>(
+      `/api/tenant/brands/${brandId}/questions/classify-metadata`,
+      payload,
+    )
+  },
+  materializeQuestions(brandId: number, payload: MaterializeQuestionsRequest) {
+    return apiClient.post<MaterializeQuestionsResult, MaterializeQuestionsRequest>(
+      `/api/tenant/brands/${brandId}/questions/materialize`,
+      payload,
+    )
+  },
   createQuestion(brandId: number, payload: QuestionRequest) {
     return apiClient.post<Question, QuestionRequest>(
       `/api/tenant/brands/${brandId}/questions`,

apps/admin-web/src/lib/errors.ts

@@ -67,7 +67,13 @@ const errorMessageMap: Record<string, string> = {
   brand_limit_reached: '品牌公司数量已达当前套餐上限',
   keyword_exists: '关键词已存在',
   keyword_limit_reached: '关键词数量已达当前套餐上限',
-  question_limit_reached: '当前关键词下的问题数量已达上限',
+  question_exists: '该品牌下已存在相同问题',
+  no_valid_questions: '没有可保存的问题，请调整候选后重试',
+  invalid_enum: '请求枚举值不合法',
+  llm_timeout: 'AI 扩展超时，AI 点已退还',
+  llm_invalid_output: 'AI 输出无法解析，AI 点已退还',
+  materialize_failed: '保存问题失败，请稍后重试',
+  question_limit_reached: '当前账号问题数量已达上限',
   knowledge_text_name_too_long: '文本名称不能超过 20 个字',
   brand_not_found: '品牌不存在或已删除',
   keyword_not_found: '关键词不存在或已删除',