feat: 引入分词能力，并新增词云子Tab

electron/main/worker/query/index.ts

@@ -80,3 +80,6 @@ export type {
   FilterResult,
   FilterMessage,
 } from './session'
+
+// NLP 查询
+export { getWordFrequency, segmentText, getPosTags } from './nlp'

electron/main/worker/query/nlp.ts

@@ -0,0 +1,137 @@
+/**
+ * NLP 查询模块
+ * 提供词频统计等 NLP 相关查询功能
+ */
+
+import { openDatabase, buildTimeFilter, type TimeFilter } from '../core'
+import { segment, batchSegmentWithFrequency, getPosTagDefinitions, collectPosTagStats } from '../../nlp'
+import type { SupportedLocale, WordFrequencyResult, WordFrequencyParams, PosTagInfo, PosTagStat } from '../../nlp'
+
+/**
+ * 获取词频统计
+ * 用于词云展示
+ */
+export function getWordFrequency(params: WordFrequencyParams): WordFrequencyResult {
+  const {
+    sessionId,
+    locale,
+    timeFilter,
+    memberId,
+    topN = 100,
+    minWordLength,
+    minCount = 2,
+    posFilterMode = 'meaningful',
+    customPosTags,
+    enableStopwords = true,
+  } = params
+
+  const db = openDatabase(sessionId)
+  if (!db) {
+    return {
+      words: [],
+      totalWords: 0,
+      totalMessages: 0,
+      uniqueWords: 0,
+    }
+  }
+
+  // 构建时间和成员过滤
+  const filter: TimeFilter = {
+    ...timeFilter,
+    memberId,
+  }
+  const { clause, params: filterParams } = buildTimeFilter(filter, 'msg')
+
+  // 构建 WHERE 子句，排除系统消息
+  let whereClause = clause
+  if (whereClause.includes('WHERE')) {
+    whereClause += " AND COALESCE(m.account_name, '') != '系统消息' AND msg.type = 0 AND msg.content IS NOT NULL AND TRIM(msg.content) != ''"
+  } else {
+    whereClause = " WHERE COALESCE(m.account_name, '') != '系统消息' AND msg.type = 0 AND msg.content IS NOT NULL AND TRIM(msg.content) != ''"
+  }
+
+  // 查询消息内容
+  const messages = db
+    .prepare(
+      `
+      SELECT msg.content
+      FROM message msg
+      JOIN member m ON msg.sender_id = m.id
+      ${whereClause}
+      `
+    )
+    .all(...filterParams) as Array<{ content: string }>
+
+  // 如果没有消息，返回空结果
+  if (messages.length === 0) {
+    return {
+      words: [],
+      totalWords: 0,
+      totalMessages: 0,
+      uniqueWords: 0,
+    }
+  }
+
+  // 提取文本内容
+  const texts = messages.map((m) => m.content)
+
+  // 收集词性统计（用于显示每个词性有多少词，仅中文有效）
+  let posTagStats: PosTagStat[] | undefined
+  if ((locale as SupportedLocale) === 'zh-CN') {
+    const posStatsMap = collectPosTagStats(
+      texts,
+      minWordLength ?? 2,
+      enableStopwords
+    )
+    posTagStats = [...posStatsMap.entries()].map(([tag, count]) => ({ tag, count }))
+  }
+
+  // 批量分词并统计词频
+  const wordFrequency = batchSegmentWithFrequency(texts, locale as SupportedLocale, {
+    minLength: minWordLength,
+    minCount,
+    topN,
+    posFilterMode,
+    customPosTags,
+    enableStopwords,
+  })
+
+  // 计算总词数（用于百分比）
+  let totalWords = 0
+  for (const count of wordFrequency.values()) {
+    totalWords += count
+  }
+
+  // 构建结果
+  const words = [...wordFrequency.entries()].map(([word, count]) => ({
+    word,
+    count,
+    percentage: totalWords > 0 ? Math.round((count / totalWords) * 10000) / 100 : 0,
+  }))
+
+  return {
+    words,
+    totalWords,
+    totalMessages: messages.length,
+    uniqueWords: wordFrequency.size,
+    posTagStats,
+  }
+}
+
+/**
+ * 单文本分词（用于调试或其他用途）
+ */
+export function segmentText(
+  text: string,
+  locale: SupportedLocale,
+  minLength?: number
+): string[] {
+  return segment(text, locale, { minLength })
+}
+
+/**
+ * 获取词性标签定义
+ */
+export function getPosTags(): PosTagInfo[] {
+  return getPosTagDefinitions()
+}