refactor(web): unify bills as UIBill, remove BillRecord

web/src/routes/analysis/+page.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
   import { onMount } from 'svelte';
   import { fetchBills, fetchMonthlyStats, checkHealth, type CleanedBill, type MonthlyStat } from '$lib/api';
+  import { cleanedBillToUIBill, type UIBill } from '$lib/models/bill';
   import { Button } from '$lib/components/ui/button';
   import { Badge } from '$lib/components/ui/badge';
   import * as Card from '$lib/components/ui/card';
@@ -74,25 +75,9 @@
     return `${year}-${String(month).padStart(2, '0')}-${String(day).padStart(2, '0')}`;
   }
   
-  // 将 CleanedBill 转换为分析服务需要的格式
-  function toAnalysisRecords(bills: CleanedBill[]) {
-    return bills.map(bill => ({
-      time: bill.time,
-      category: bill.category,
-      merchant: bill.merchant,
-      description: bill.description,
-      income_expense: bill.income_expense,
-      amount: String(bill.amount),
-      payment_method: bill.pay_method,
-      status: bill.status,
-      remark: bill.remark,
-      needs_review: bill.review_level,
-    }));
-  }
-  
-  // 派生分析数据
-  let analysisRecords = $derived(isDemo ? demoRecords : toAnalysisRecords(records));
-  let allAnalysisRecords = $derived(isDemo ? demoRecords : toAnalysisRecords(allRecords)); // 全部数据用于每日趋势图
+  // 派生分析数据（统一成 UIBill）
+  let analysisRecords: UIBill[] = $derived.by(() => (isDemo ? demoRecords : records.map(cleanedBillToUIBill)));
+  let allAnalysisRecords: UIBill[] = $derived.by(() => (isDemo ? demoRecords : allRecords.map(cleanedBillToUIBill)));
   let categoryStats = $derived(calculateCategoryStats(analysisRecords));
   let dailyExpenseData = $derived(calculateDailyExpenseData(analysisRecords));