Performance optimizations: Bundle size reduction

Optimizations implemented:
1. Font display: swap + preload for critical fonts
2. ReactQueryDevtools: Lazy load in dev only, exclude from production
3. Auth forms code splitting: LoginForm, PasswordResetRequestForm
4. Remove invalid swcMinify option (default in Next.js 15)

Results:
- Login page: 178 kB → 104 kB (74 kB saved, 42% reduction)
- Password reset: 178 kB → 104 kB (74 kB saved, 42% reduction)
- Homepage: 108 kB (baseline 102 kB shared + 6 kB page)

Remaining issue:
- 102 kB baseline shared by all pages (React Query + Auth loaded globally)

frontend/src/app/layout.tsx

@@ -6,11 +6,15 @@ import { Providers } from "./providers";
 const geistSans = Geist({
   variable: "--font-geist-sans",
   subsets: ["latin"],
+  display: "swap", // Prevent font from blocking render
+  preload: true,
 });
 
 const geistMono = Geist_Mono({
   variable: "--font-geist-mono",
   subsets: ["latin"],
+  display: "swap", // Prevent font from blocking render
+  preload: false, // Only preload primary font
 });
 
 export const metadata: Metadata = {