feat: add upstream model sync frontend API

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

frontend/src/i18n/locales/en.ts

@@ -3216,6 +3216,13 @@ export default {
       searchModels: 'Search models...',
       noMatchingModels: 'No matching models',
       fillRelatedModels: 'Sync latest supported models',
+      syncUpstreamModels: 'Sync upstream supported models',
+      syncUpstreamModelsLoading: 'Syncing upstream...',
+      syncUpstreamModelsSuccess: 'Synced {count} new model(s) from upstream ({total} upstream total)',
+      syncUpstreamModelsNoChanges: 'All {count} upstream model(s) are already in the whitelist',
+      syncUpstreamModelsEmpty: 'Upstream returned no models to sync',
+      syncUpstreamModelsFailed: 'Failed to sync upstream models',
+      syncUpstreamModelsError: 'Failed to sync upstream models: {message}',
       clearAllModels: 'Clear all models',
       customModelName: 'Custom model name',
       enterCustomModelName: 'Enter custom model name',

frontend/src/i18n/locales/zh.ts

@@ -3360,6 +3360,13 @@ export default {
       searchModels: '搜索模型...',
       noMatchingModels: '没有匹配的模型',
       fillRelatedModels: '同步最新支持模型',
+      syncUpstreamModels: '同步上游支持的模型',
+      syncUpstreamModelsLoading: '同步上游中...',
+      syncUpstreamModelsSuccess: '已从上游同步 {count} 个新模型（上游共 {total} 个）',
+      syncUpstreamModelsNoChanges: '上游 {count} 个模型均已在白名单中',
+      syncUpstreamModelsEmpty: '上游没有返回可同步的模型',
+      syncUpstreamModelsFailed: '同步上游模型失败',
+      syncUpstreamModelsError: '同步上游模型失败：{message}',
       clearAllModels: '清除所有模型',
       customModelName: '自定义模型名称',
       enterCustomModelName: '输入自定义模型名称',