feat: light theme, frontend link, nav fix, rename to 七虎AI

frontend/src/pages/admin/SiteSettings.tsx

@@ -312,7 +312,7 @@ const SiteSettings: React.FC = () => {
               <FormGroup label="网站名称" required>
                 <input className="admin-form-input" value={brand.siteName}
                   onChange={e => setBrand({ ...brand, siteName: e.target.value })}
-                  placeholder="例如: Qihu-AIFlow" />
+                  placeholder="例如: 七虎AI" />
               </FormGroup>
               <FormGroup label="LOGO URL">
                 <input className="admin-form-input" value={brand.logo}
@@ -638,7 +638,7 @@ const SiteSettings: React.FC = () => {
                 value={registration.welcome_message}
                 onChange={e => setRegistration({ ...registration, welcome_message: e.target.value })}
                 style={{ minHeight: 80 }}
-                placeholder="欢迎加入 Qihu-AIFlow！从这里开始你的 AI 创造之旅..." />
+                placeholder="欢迎加入七虎AI！从这里开始你的 AI 创造之旅..." />
             </FormGroup>
 
             <FormActions>