Fix cron expression validation for 6-field format (with seconds)

[Copilot]

Frontend validation rejected cron expressions with seconds field (e.g., */8 * * * * ?). Backend validation already worked correctly.

Root Cause

Default import of cron-parser fails when bundled for browser:

import CronExpressionParser from 'cron-parser';
// CronExpressionParser.parse() is undefined after webpack bundling

TypeScript's esModuleInterop handles this correctly for CommonJS backend, but frontend bundler does not.

Changes

Use named export instead:

-import CronExpressionParser from 'cron-parser';
+import { CronExpressionParser } from 'cron-parser';

Applied to:

• src/pages/crontab/modal.tsx
• src/pages/subscription/modal.tsx
• src/utils/index.ts

Both 5-field (* * * * *) and 6-field (* * * * * *) cron expressions now validate correctly.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>新建定时任务时候 如果corn表达式有秒 那么不会创建成功</issue_title>
<issue_description>### Qinglong version

2.20.1

Steps to reproduce

What is expected?

corn可以兼容秒级

What is actually happening?

corn不支持秒

System Info

Need to install the following packages:
  envinfo
Ok to proceed? (y) y

  System:
    OS: Windows 11 10.0.22635
    CPU: (12) x64 AMD Ryzen 5 5600 6-Core Processor
    Memory: 5.71 GB / 15.93 GB
  Binaries:
    Node: 16.13.0 - C:\Program Files\nodejs\node.EXE
    npm: 8.1.0 - C:\Program Files\nodejs\npm.CMD
    pnpm: 9.10.0 - C:\Users\24786\AppData\Local\pnpm\pnpm.EXE
  Browsers:
    Chrome: 143.0.7499.170
    Edge: Chromium (142.0.3595.53)
    Internet Explorer: 11.0.22621.3566

Any additional comments?

No response</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes 新建定时任务时候 如果corn表达式有秒 那么不会创建成功 #2915

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Project	Deployment	Review	Updated (UTC)
qinglong	Ready	Preview, Comment	Jan 29, 2026 11:47am
qinglong-back	Ready	Preview, Comment	Jan 29, 2026 11:47am