🚀 feat(frontend): add robust boolean handling across settings pages

Summary
-------
1. Introduced a reusable `toBoolean` utility (`web/src/helpers/boolean.js`) that converts
   strings (`'true'/'false'`, `'1'/'0'`), numbers, and native booleans to a proper boolean.
2. Re-exported `toBoolean` via `web/src/helpers/index.js` for simple one-line imports.

Refactors
---------
• Systematically replaced all legacy `item.value === 'true'` checks with `toBoolean(item.value)` in
  the following components:
  – `SystemSetting.js`
  – `OperationSetting.js`
  – `PaymentSetting.js`
  – `RatioSetting.js`
  – `RateLimitSetting.js`
  – `ModelSetting.js`
  – `DrawingSetting.js`
  – `DashboardSetting.js`
  – `ChatsSetting.js`

• Unified import statements to
  `import { …, toBoolean } from '../../helpers';`
  removing redundant `../../helpers/boolean` paths.

Why
---
SQLite sometimes returns `1/0` or boolean literals instead of the string `'true'/'false'`, causing
checkbox states to reset on page reload. The new utility guarantees consistent boolean parsing,
fixing the issue across all environments (SQLite, MySQL, etc.) while improving code clarity.

web/src/components/settings/PaymentSetting.js

@@ -2,7 +2,7 @@ import React, { useEffect, useState } from 'react';
 import { Card, Spin } from '@douyinfe/semi-ui';
 import SettingsGeneralPayment from '../../pages/Setting/Payment/SettingsGeneralPayment.js';
 import SettingsPaymentGateway from '../../pages/Setting/Payment/SettingsPaymentGateway.js';
-import { API, showError } from '../../helpers';
+import { API, showError, toBoolean } from '../../helpers';
 import { useTranslation } from 'react-i18next';
 
 const PaymentSetting = () => {
@@ -42,7 +42,7 @@ const PaymentSetting = () => {
             break;
           default:
             if (item.key.endsWith('Enabled')) {
-              newInputs[item.key] = item.value === 'true' ? true : false;
+              newInputs[item.key] = toBoolean(item.value);
             } else {
               newInputs[item.key] = item.value;
             }