feat: 添加 AI 分类功能，支持交易自动分类与标签生成

src/services/ai/aiService.js

@@ -0,0 +1,63 @@
+import { buildTransactionEnrichmentMessages } from '../../lib/aiPrompt.js'
+import { useSettingsStore } from '../../stores/settings.js'
+import {
+  applyAiEnrichment,
+  fetchRecentTransactionsForAi,
+  markTransactionAiFailed,
+} from '../transactionService.js'
+import { DeepSeekProvider } from './deepseekProvider.js'
+
+const clampThreshold = (value) => {
+  const numeric = Number(value)
+  if (!Number.isFinite(numeric)) return 0.9
+  return Math.min(Math.max(numeric, 0), 1)
+}
+
+const createProvider = (settingsStore) => {
+  if (settingsStore.aiProvider !== 'deepseek') {
+    throw new Error(`Unsupported AI provider: ${settingsStore.aiProvider}`)
+  }
+
+  return new DeepSeekProvider({
+    apiKey: settingsStore.aiApiKey,
+    model: settingsStore.aiModel,
+  })
+}
+
+export const isAiReady = (settingsStore = useSettingsStore()) =>
+  !!settingsStore.aiAutoCategoryEnabled && !!settingsStore.aiApiKey
+
+export const maybeEnrichTransactionWithAi = async (transaction) => {
+  if (!transaction?.id) return transaction
+
+  const settingsStore = useSettingsStore()
+  if (!isAiReady(settingsStore)) {
+    return transaction
+  }
+
+  try {
+    const provider = createProvider(settingsStore)
+    const similarTransactions = await fetchRecentTransactionsForAi(6, transaction.id)
+    const messages = buildTransactionEnrichmentMessages({
+      transaction,
+      similarTransactions,
+    })
+    const result = await provider.enrichTransaction({ messages })
+    const threshold = clampThreshold(settingsStore.aiAutoApplyThreshold)
+
+    const updated = await applyAiEnrichment(transaction.id, result.normalized, {
+      applyCategory: result.normalized.confidence >= threshold,
+      model: result.model,
+    })
+
+    return updated || transaction
+  } catch (error) {
+    console.warn('[ai] transaction enrichment failed', error)
+    const failed = await markTransactionAiFailed(
+      transaction.id,
+      error?.message || 'AI enrichment failed',
+      settingsStore.aiModel,
+    )
+    return failed || transaction
+  }
+}