Revert "revert: roll back v12.3.3 (Issue Blowout 2026)"

This reverts commit bfc7de377a.

src/ui/viewer/hooks/useSettings.ts

@@ -3,6 +3,7 @@ import { Settings } from '../types';
 import { DEFAULT_SETTINGS } from '../constants/settings';
 import { API_ENDPOINTS } from '../constants/api';
 import { TIMING } from '../constants/timing';
+import { authFetch } from '../utils/api';
 
 export function useSettings() {
   const [settings, setSettings] = useState<Settings>(DEFAULT_SETTINGS);
@@ -11,8 +12,13 @@ export function useSettings() {
 
   useEffect(() => {
     // Load initial settings
-    fetch(API_ENDPOINTS.SETTINGS)
-      .then(res => res.json())
+    authFetch(API_ENDPOINTS.SETTINGS)
+      .then(async res => {
+        if (!res.ok) {
+          throw new Error(`Failed to load settings (${res.status})`);
+        }
+        return res.json();
+      })
       .then(data => {
         // Use ?? (nullish coalescing) instead of || so that falsy values
         // like '0', 'false', and '' from the backend are preserved.
@@ -60,20 +66,30 @@ export function useSettings() {
     setIsSaving(true);
     setSaveStatus('Saving...');
 
-    const response = await fetch(API_ENDPOINTS.SETTINGS, {
-      method: 'POST',
-      headers: { 'Content-Type': 'application/json' },
-      body: JSON.stringify(newSettings)
-    });
+    try {
+      const response = await authFetch(API_ENDPOINTS.SETTINGS, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify(newSettings)
+      });
 
-    const result = await response.json();
+      if (!response.ok) {
+        setSaveStatus(`✗ Error: ${response.status === 401 ? 'Unauthorized' : response.statusText}`);
+        setIsSaving(false);
+        return;
+      }
 
-    if (result.success) {
-      setSettings(newSettings);
-      setSaveStatus('✓ Saved');
-      setTimeout(() => setSaveStatus(''), TIMING.SAVE_STATUS_DISPLAY_DURATION_MS);
-    } else {
-      setSaveStatus(`✗ Error: ${result.error}`);
+      const result = await response.json();
+
+      if (result.success) {
+        setSettings(newSettings);
+        setSaveStatus('✓ Saved');
+        setTimeout(() => setSaveStatus(''), TIMING.SAVE_STATUS_DISPLAY_DURATION_MS);
+      } else {
+        setSaveStatus(`✗ Error: ${result.error}`);
+      }
+    } catch (error) {
+      setSaveStatus(`✗ Error: ${error instanceof Error ? error.message : 'Network error'}`);
     }
 
     setIsSaving(false);