Refactor API key handling in AssistantPage and ComponentsModelsPage

- Update AssistantPage to use a stored value mask for API keys, improving security and user experience.
- Modify ComponentsModelsPage to display the current API key contextually, enhancing clarity for users.
- Adjust related components to ensure consistent handling of API key visibility and management.

frontend/src/components/pages/ComponentsModelsPage.tsx

@@ -696,6 +696,14 @@ export function ComponentsModelsPage() {
               >
                 API Key
               </FieldLabel>
+              {hasStoredApiKey && (
+                <div className="mb-2 flex items-center gap-2 text-xs text-muted-foreground">
+                  <span>当前密钥</span>
+                  <code className="rounded-md bg-surface-strong px-2 py-1 font-mono text-foreground">
+                    {editingModel?.apiKey}
+                  </code>
+                </div>
+              )}
               <div className="relative">
                 <Input
                   id="model-api-key"
@@ -722,7 +730,7 @@ export function ComponentsModelsPage() {
               </div>
               {hasStoredApiKey && (
                 <p className="mt-2 text-xs leading-5 text-muted-foreground">
-                  已有密钥不会返回浏览器。留空可保持原密钥，输入新值将覆盖原密钥。
+                  仅显示当前密钥首尾用于识别。留空可保持原密钥，输入新值将覆盖原密钥。
                 </p>
               )}
             </div>