feat: add optimistic locking and improve type safety

- Implement optimistic locking for deposit balance updates
  - Prevent race conditions in concurrent deposit requests
  - Add automatic retry with exponential backoff (max 3 attempts)
  - Add version column to user_deposits table

- Improve type safety across codebase
  - Add explicit types for Namecheap API responses
  - Add typed function arguments (ManageDepositArgs, etc.)
  - Remove `any` types from deposit-agent and tool files

- Add reconciliation job for balance integrity verification
  - Compare user_deposits.balance vs SUM(confirmed transactions)
  - Alert admin on discrepancy detection

- Set up test environment with Vitest + Miniflare
  - Add 50+ test cases for deposit system
  - Add helper functions for test data creation

- Update documentation
  - Add migration guide for version columns
  - Document optimistic locking patterns

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/index.ts

@@ -5,6 +5,7 @@ import { handleApiRequest } from './routes/api';
 import { handleHealthCheck } from './routes/health';
 import { parseBankSMS } from './services/bank-sms-parser';
 import { matchPendingDeposit } from './services/deposit-matcher';
+import { reconcileDeposits, formatReconciliationReport } from './utils/reconciliation';
 
 export default {
   // HTTP 요청 핸들러
@@ -229,5 +230,29 @@ Documentation: https://github.com/your-repo
     } catch (error) {
       console.error('[Cron] 오류:', error);
     }
+
+    // 예치금 정합성 검증 (Reconciliation)
+    console.log('[Cron] 예치금 정합성 검증 시작');
+    try {
+      const report = await reconcileDeposits(env.DB);
+
+      if (report.inconsistencies > 0) {
+        // 관리자 알림 전송
+        const adminId = env.DEPOSIT_ADMIN_ID;
+        if (adminId) {
+          const message = formatReconciliationReport(report);
+          await sendMessage(env.BOT_TOKEN, parseInt(adminId), message).catch(err => {
+            console.error('[Cron] 정합성 검증 알림 전송 실패:', err);
+          });
+        } else {
+          console.warn('[Cron] DEPOSIT_ADMIN_ID 미설정 - 알림 전송 불가');
+        }
+      }
+
+      console.log(`[Cron] 정합성 검증 완료: ${report.totalUsers}명 검증, ${report.inconsistencies}건 불일치`);
+    } catch (error) {
+      console.error('[Cron] 정합성 검증 실패:', error);
+      // 정합성 검증 실패가 전체 Cron을 중단시키지 않도록 에러를 catch만 하고 계속 진행
+    }
   },
 };