feat: websearch quota enhancements and balance notify hint

- QuotaLimit changed to *int64 (null=unlimited, >0=limited)
- Add reset-usage endpoint (POST /admin/settings/web-search-emulation/reset-usage)
- Show quota usage in header always (collapsed and expanded)
- Add reset quota button in expanded provider view
- Quota input: empty=unlimited with ∞ placeholder, must be >0 if set
- Add email verification hint on balance notify card

frontend/src/api/admin/settings.ts

@@ -502,7 +502,7 @@ export interface WebSearchProviderConfig {
   type: 'brave' | 'tavily'
   api_key: string
   api_key_configured: boolean
-  quota_limit: number
+  quota_limit: number | null
   subscribed_at: number | null
   quota_used?: number
   proxy_id: number | null
@@ -547,6 +547,12 @@ export async function testWebSearchEmulation(
   return data
 }
 
+export async function resetWebSearchUsage(
+  payload: { provider_type: string }
+): Promise<void> {
+  await apiClient.post('/admin/settings/web-search-emulation/reset-usage', payload)
+}
+
 export const settingsAPI = {
   getSettings,
   updateSettings,
@@ -565,7 +571,8 @@ export const settingsAPI = {
   updateBetaPolicySettings,
   getWebSearchEmulationConfig,
   updateWebSearchEmulationConfig,
-  testWebSearchEmulation
+  testWebSearchEmulation,
+  resetWebSearchUsage
 }
 
 export default settingsAPI

frontend/src/components/user/profile/ProfileBalanceNotifyCard.vue

@@ -48,6 +48,7 @@
         <!-- Email list with toggles -->
         <div>
           <label class="input-label">{{ t('profile.balanceNotify.extraEmails') }}</label>
+          <p class="mb-2 text-xs text-yellow-600 dark:text-yellow-400">{{ t('profile.balanceNotify.extraEmailsHint') }}</p>
 
           <!-- Saved email entries -->
           <div v-if="emailEntries.length > 0" class="space-y-2 mb-3">

frontend/src/i18n/locales/en.ts

@@ -914,6 +914,7 @@ export default {
       thresholdPlaceholder: 'Enter amount',
       systemDefault: 'System Default',
       extraEmails: 'Notification Emails',
+      extraEmailsHint: 'You must add and verify an email address to receive low balance alerts',
       primaryEmail: 'Primary',
       noExtraEmails: 'No extra notification emails',
       enterEmail: 'Enter email address',
@@ -4435,10 +4436,14 @@ export default {
         copyApiKey: 'Copy',
         copied: 'Copied',
         quotaLimit: 'Quota Limit',
-        quotaLimitHint: '0 = unlimited',
+        quotaLimitHint: 'Leave empty for unlimited; must be > 0 if set',
+        quotaLimitMustBePositive: 'Quota limit must be greater than 0',
         subscribedAt: 'Subscribed At',
-        subscribedAtHint: 'Quota resets monthly from this date',
+        subscribedAtHint: 'Quota resets monthly from this date; leave empty to disable auto-reset',
         quotaUsage: 'Usage',
+        resetUsage: 'Reset',
+        resetUsageConfirm: 'Reset usage counter for this provider?',
+        resetUsageSuccess: 'Usage counter reset',
         proxy: 'Proxy',
         removeProvider: 'Remove',
         noProviders: 'No search providers configured',

frontend/src/i18n/locales/zh.ts

@@ -918,6 +918,7 @@ export default {
       thresholdPlaceholder: '输入金额',
       systemDefault: '系统默认值',
       extraEmails: '通知邮箱',
+      extraEmailsHint: '必须添加并验证邮箱后，余额不足时才能收到提醒邮件',
       primaryEmail: '主邮箱',
       noExtraEmails: '暂无额外通知邮箱',
       enterEmail: '输入邮箱地址',
@@ -4597,10 +4598,14 @@ export default {
         copyApiKey: '复制',
         copied: '已复制',
         quotaLimit: '配额上限',
-        quotaLimitHint: '0 表示无限制',
+        quotaLimitHint: '留空表示无限制；填写时必须大于 0',
+        quotaLimitMustBePositive: '配额上限必须大于 0',
         subscribedAt: '订阅时间',
-        subscribedAtHint: '配额从此日期起每月自动重置',
+        subscribedAtHint: '配额从此日期起每月自动重置；留空则不自动重置',
         quotaUsage: '用量',
+        resetUsage: '重置',
+        resetUsageConfirm: '确定要重置此服务商的用量计数吗？',
+        resetUsageSuccess: '用量已重置',
         proxy: '代理',
         removeProvider: '删除',
         noProviders: '未配置搜索服务商',

frontend/src/views/admin/SettingsView.vue

@@ -1774,9 +1774,9 @@
                       class="w-36"
                       @click.stop
                     />
-                    <!-- Quota summary in collapsed state -->
-                    <span v-if="!expandedProviders[pIdx]" class="text-xs text-gray-400">
-                      {{ provider.quota_used ?? 0 }} / {{ provider.quota_limit > 0 ? provider.quota_limit : '∞' }}
+                    <!-- Quota summary (always visible) -->
+                    <span class="text-xs text-gray-400">
+                      {{ provider.quota_used ?? 0 }} / {{ provider.quota_limit != null && provider.quota_limit > 0 ? provider.quota_limit : '∞' }}
                     </span>
                     <span v-if="!expandedProviders[pIdx] && provider.api_key_configured" class="text-xs text-green-500">
                       {{ t('admin.settings.webSearchEmulation.apiKeyConfigured') }}
@@ -1835,7 +1835,7 @@
                   <div class="grid grid-cols-2 gap-3">
                     <div>
                       <label class="text-xs text-gray-500">{{ t('admin.settings.webSearchEmulation.quotaLimit') }}</label>
-                      <input v-model.number="provider.quota_limit" type="number" min="0" class="input text-sm" />
+                      <input v-model="provider.quota_limit" type="number" min="1" class="input text-sm" :placeholder="'∞'" />
                       <p class="mt-0.5 text-xs text-gray-400">{{ t('admin.settings.webSearchEmulation.quotaLimitHint') }}</p>
                     </div>
                     <div>
@@ -1853,7 +1853,7 @@
                   <!-- Usage display -->
                   <div class="flex items-center gap-2">
                     <span class="text-xs text-gray-500">{{ t('admin.settings.webSearchEmulation.quotaUsage') }}:</span>
-                    <div v-if="provider.quota_limit > 0" class="flex-1 rounded-full bg-gray-200 dark:bg-dark-600" style="height: 6px">
+                    <div v-if="provider.quota_limit != null && provider.quota_limit > 0" class="flex-1 rounded-full bg-gray-200 dark:bg-dark-600" style="height: 6px">
                       <div
                         class="h-full rounded-full transition-all"
                         :class="quotaPercentage(provider) > 90 ? 'bg-red-500' : quotaPercentage(provider) > 70 ? 'bg-yellow-500' : 'bg-green-500'"
@@ -1861,7 +1861,15 @@
                       />
                     </div>
                     <div v-else class="flex-1" />
-                    <span class="text-xs text-gray-500">{{ provider.quota_used ?? 0 }} / {{ provider.quota_limit > 0 ? provider.quota_limit : '∞' }}</span>
+                    <span class="text-xs text-gray-500">{{ provider.quota_used ?? 0 }} / {{ provider.quota_limit != null && provider.quota_limit > 0 ? provider.quota_limit : '∞' }}</span>
+                    <button
+                      v-if="(provider.quota_used ?? 0) > 0"
+                      type="button"
+                      class="text-xs text-primary-600 hover:text-primary-700"
+                      @click="resetWebSearchUsage(pIdx)"
+                    >
+                      {{ t('admin.settings.webSearchEmulation.resetUsage') }}
+                    </button>
                   </div>
 
                   <!-- Proxy + Test on same row -->
@@ -3118,6 +3126,19 @@ function quotaPercentage(provider: WebSearchProviderConfig): number {
   return ((provider.quota_used ?? 0) / provider.quota_limit) * 100
 }
 
+async function resetWebSearchUsage(idx: number) {
+  const provider = webSearchConfig.providers[idx]
+  if (!provider) return
+  if (!confirm(t('admin.settings.webSearchEmulation.resetUsageConfirm'))) return
+  try {
+    await adminAPI.settings.resetWebSearchUsage({ provider_type: provider.type })
+    provider.quota_used = 0
+    appStore.showSuccess(t('admin.settings.webSearchEmulation.resetUsageSuccess'))
+  } catch (err: unknown) {
+    appStore.showError(extractApiErrorMessage(err, t('common.error')))
+  }
+}
+
 async function copyApiKey(idx: number) {
   const key = webSearchConfig.providers[idx]?.api_key
   if (!key) {
@@ -3167,9 +3188,16 @@ async function loadWebSearchConfig() {
 
 async function saveWebSearchConfig(): Promise<boolean> {
   try {
+    for (const p of webSearchConfig.providers) {
+      const raw = p.quota_limit
+      if (raw != null && Number(raw) !== 0 && Number(raw) < 1) {
+        appStore.showError(t('admin.settings.webSearchEmulation.quotaLimitMustBePositive'))
+        return false
+      }
+    }
     const providers = webSearchConfig.providers.map((p: WebSearchProviderConfig) => ({
       ...p,
-      quota_limit: typeof p.quota_limit === 'number' && p.quota_limit > 0 ? p.quota_limit : 0,
+      quota_limit: Number(p.quota_limit) > 0 ? Number(p.quota_limit) : null,
     }))
     await adminAPI.settings.updateWebSearchEmulationConfig({
       enabled: webSearchConfig.enabled,