feat: restyle API Key quota limit UI to card/toggle format

- Redesign quota limit section with card layout and toggle switch
- Add watch to clear quota value when toggle is disabled
- Add i18n keys for toggle labels and hints (zh/en)
- Bump version to 0.1.90.5

frontend/src/i18n/locales/en.ts

@@ -1787,6 +1787,10 @@ export default {
       quotaLimit: 'Quota Limit',
       quotaLimitPlaceholder: '0 means unlimited',
       quotaLimitHint: 'Set max spending limit (USD). Account will be paused when reached. Changing limit won\'t reset usage.',
+      quotaLimitToggle: 'Enable Quota Limit',
+      quotaLimitToggleHint: 'When enabled, account will be paused when usage reaches the set limit',
+      quotaLimitAmount: 'Limit Amount',
+      quotaLimitAmountHint: 'Maximum spending limit (USD). Account will be auto-paused when reached. Changing limit won\'t reset usage.',
       testConnection: 'Test Connection',
       reAuthorize: 'Re-Authorize',
       refreshToken: 'Refresh Token',

frontend/src/i18n/locales/zh.ts

@@ -1794,6 +1794,10 @@ export default {
       quotaLimit: '配额限制',
       quotaLimitPlaceholder: '0 表示不限制',
       quotaLimitHint: '设置最大使用额度（美元），达到后账号暂停调度。修改限额不会重置已用额度。',
+      quotaLimitToggle: '启用配额限制',
+      quotaLimitToggleHint: '开启后，当账号用量达到设定额度时自动暂停调度',
+      quotaLimitAmount: '限额金额',
+      quotaLimitAmountHint: '账号最大可用额度（美元），达到后自动暂停。修改限额不会重置已用额度。',
       testConnection: '测试连接',
       reAuthorize: '重新授权',
       refreshToken: '刷新令牌',