fix(web): validate question input before divination and fix logout flow

- Add validation for question text in ManualDivinationPage and AutoDivinationPage
- Fix logout flow to call backend API before clearing local auth
- Show error message when question is empty before starting interpretation

web/src/components/AutoDivinationPage.tsx

@@ -422,6 +422,10 @@ export default function AutoDivinationPage({ locale, divination: d }: Props) {
 
   const handleSubmit = () => {
     if (!done) return;
+    if (!question.trim()) {
+      setErrorMessage(locale === 'en' ? 'Please enter your question before starting the interpretation.' : '请输入您要占卜的问题后再开始解卦。');
+      return;
+    }
     setShowConfirm(true);
   };
 

web/src/components/ManualDivinationPage.tsx

@@ -440,6 +440,10 @@ export default function ManualDivinationPage({ locale, divination: d }: Props) {
   const showNextGuide = () => setGuideStep((step) => (step === null ? 0 : Math.min(step + 1, text.guideSteps.length - 1)));
 
   const handleSubmit = () => {
+    if (!question.trim()) {
+      setErrorMessage(locale === 'en' ? 'Please enter your question before starting the interpretation.' : '请输入您要占卜的问题后再开始解卦。');
+      return;
+    }
     setShowConfirm(true);
   };
 

web/src/components/SettingsPage.tsx

@@ -21,11 +21,14 @@ export default function SettingsPage({ locale, settings: s }: Props) {
     if (!confirm(s.logoutConfirm)) return;
 
     setLogoutLoading(true);
-    // Clear local auth immediately and redirect
+    try {
+      // Call backend logout first (needs auth)
+      await logout();
+    } catch {
+      // Ignore logout API errors
+    }
+    // Clear local auth and redirect
     clearAuth();
-    // Fire backend logout in background (don't wait)
-    logout().catch(() => {});
-    // Redirect to login
     redirectToLogin();
   };