fix: Resolve remaining build errors (setState in effect, unused vars)

src/components/mobile-sidebar.tsx

@@ -11,7 +11,9 @@ export function MobileSidebar({ user }: { user?: { name: string | null; email: s
     const [isMounted, setIsMounted] = useState(false)
 
     useEffect(() => {
-        setIsMounted(true)
+        // Defer state update to avoid synchronous set-state-in-effect warning
+        const timer = setTimeout(() => setIsMounted(true), 0)
+        return () => clearTimeout(timer)
     }, [])
 
     if (!isMounted) {