feat: manage splash logo media via payload

src/spa/components/layout/Layout.tsx

@@ -156,7 +156,13 @@ const Layout: React.FC<LayoutProps> = ({ children, header = defaultHeaderData, f
       style={{ paddingTop: 60, paddingLeft: 0 }}
       className="min-h-screen flex flex-col bg-background text-foreground font-body"
     >
-      {showLoader && <LoadingScreen onDone={() => setShowLoader(false)} />}
+      {showLoader && (
+        <LoadingScreen
+          logoAlt={header.logo?.alt || header.overlayLogoAlt}
+          logoSrc={logo}
+          onDone={() => setShowLoader(false)}
+        />
+      )}
 
       {/* ── GLOBAL BAYERN CSS ────────────────────────── */}
       <style>{`