diff --git a/src/api/branding.ts b/src/api/branding.ts
index 8dfc21c..2073e8c 100644
--- a/src/api/branding.ts
+++ b/src/api/branding.ts
@@ -46,25 +46,32 @@ export const isLogoPreloaded = (): boolean => {
   }
 };
 
-// Get cached branding from localStorage
+// Get cached branding from sessionStorage
 export const getCachedBranding = (): BrandingInfo | null => {
   try {
-    const cached = localStorage.getItem(BRANDING_CACHE_KEY);
+    const cached = sessionStorage.getItem(BRANDING_CACHE_KEY);
     if (cached) {
       return JSON.parse(cached);
     }
+    // One-time migration: move stale localStorage value to sessionStorage
+    const legacy = localStorage.getItem(BRANDING_CACHE_KEY);
+    if (legacy) {
+      localStorage.removeItem(BRANDING_CACHE_KEY);
+      sessionStorage.setItem(BRANDING_CACHE_KEY, legacy);
+      return JSON.parse(legacy);
+    }
   } catch {
-    // localStorage not available or invalid JSON
+    // storage not available or invalid JSON
   }
   return null;
 };
 
-// Update branding cache in localStorage
+// Update branding cache in sessionStorage
 export const setCachedBranding = (branding: BrandingInfo) => {
   try {
-    localStorage.setItem(BRANDING_CACHE_KEY, JSON.stringify(branding));
+    sessionStorage.setItem(BRANDING_CACHE_KEY, JSON.stringify(branding));
   } catch {
-    // localStorage not available
+    // sessionStorage not available
   }
 };
 
diff --git a/src/components/layout/AppShell/AppHeader.tsx b/src/components/layout/AppShell/AppHeader.tsx
index 84d6ee0..1ff846d 100644
--- a/src/components/layout/AppShell/AppHeader.tsx
+++ b/src/components/layout/AppShell/AppHeader.tsx
@@ -93,6 +93,7 @@ export function AppHeader({
       return data;
     },
     initialData: getCachedBranding() ?? undefined,
+    initialDataUpdatedAt: 0,
     staleTime: 60000,
     refetchOnWindowFocus: true,
     retry: 1,
diff --git a/src/components/layout/AppShell/Aurora.tsx b/src/components/layout/AppShell/Aurora.tsx
index 7cbd365..278f70f 100644
--- a/src/components/layout/AppShell/Aurora.tsx
+++ b/src/components/layout/AppShell/Aurora.tsx
@@ -127,7 +127,30 @@ function generateColorStops(background: string, surface: string, accent: string)
   return [background, surface, dimAccent(accent)];
 }
 
+let _webglAvailable: boolean | null = null;
+
+function isWebglAvailable(): boolean {
+  if (_webglAvailable === null) {
+    try {
+      const renderer = new Renderer({
+        alpha: true,
+        antialias: false,
+        powerPreference: 'low-power',
+      });
+      _webglAvailable = !!renderer.gl;
+    } catch {
+      _webglAvailable = false;
+    }
+  }
+  return _webglAvailable;
+}
+
 export function Aurora() {
+  if (!isWebglAvailable()) return null;
+  return <AuroraImpl />;
+}
+
+function AuroraImpl() {
   const containerRef = useRef<HTMLDivElement>(null);
   const animationFrameRef = useRef<number>(0);
   const rendererRef = useRef<Renderer | null>(null);
diff --git a/src/components/layout/AppShell/DesktopSidebar.tsx b/src/components/layout/AppShell/DesktopSidebar.tsx
index 2f826a5..8f36328 100644
--- a/src/components/layout/AppShell/DesktopSidebar.tsx
+++ b/src/components/layout/AppShell/DesktopSidebar.tsx
@@ -62,6 +62,7 @@ export function DesktopSidebar({
       return data;
     },
     initialData: getCachedBranding() ?? undefined,
+    initialDataUpdatedAt: 0,
     staleTime: 60000,
     refetchOnWindowFocus: true,
     retry: 1,
diff --git a/src/hooks/useBranding.ts b/src/hooks/useBranding.ts
index c827ea4..125ab15 100644
--- a/src/hooks/useBranding.ts
+++ b/src/hooks/useBranding.ts
@@ -27,6 +27,7 @@ export function useBranding() {
       return data;
     },
     initialData: getCachedBranding() ?? undefined,
+    initialDataUpdatedAt: 0,
     staleTime: 60000,
     enabled: isAuthenticated,
   });
diff --git a/src/pages/Login.tsx b/src/pages/Login.tsx
index 2f27756..edc9e53 100644
--- a/src/pages/Login.tsx
+++ b/src/pages/Login.tsx
@@ -90,6 +90,7 @@ export default function Login() {
     },
     staleTime: 60000,
     initialData: cachedBranding ?? undefined,
+    initialDataUpdatedAt: 0,
   });
 
   // Check if email auth is enabled