feat(ui): enhance provider form with brand icons and colors

- Add Save icon to submit buttons in provider forms
- Replace generic Zap icon with brand-specific icons (ClaudeIcon, CodexIcon)
- Update selected state colors: Claude uses brand color #D97757, Codex uses black
- Maintain visual consistency with AppSwitcher component

src/components/ProviderForm.tsx

@@ -15,7 +15,7 @@ import ApiKeyInput from "./ProviderForm/ApiKeyInput";
 import ClaudeConfigEditor from "./ProviderForm/ClaudeConfigEditor";
 import CodexConfigEditor from "./ProviderForm/CodexConfigEditor";
 import KimiModelSelector from "./ProviderForm/KimiModelSelector";
-import { X, AlertCircle } from "lucide-react";
+import { X, AlertCircle, Save } from "lucide-react";
 // 分类仅用于控制少量交互（如官方禁用 API Key），不显示介绍组件
 
 interface ProviderFormProps {
@@ -936,8 +936,9 @@ const ProviderForm: React.FC<ProviderFormProps> = ({
             </button>
             <button
               type="submit"
-              className="px-4 py-2 bg-blue-500 text-white rounded-lg hover:bg-blue-600 transition-colors text-sm font-medium"
+              className="px-4 py-2 bg-blue-500 text-white rounded-lg hover:bg-blue-600 transition-colors text-sm font-medium flex items-center gap-2"
             >
+              <Save className="w-4 h-4" />
               {submitText}
             </button>
           </div>