refactor: reorganize project structure following go standards

web/templates/not_found.templ

@@ -0,0 +1,12 @@
+package templates
+
+templ NotFoundPage() {
+	@Layout("mal - not found", false) {
+		<section class="w-full max-w-3xl min-h-dvh mx-auto grid content-center justify-items-center gap-3 px-7 py-8 text-center">
+			<p class="m-0 text-6xl leading-none tracking-wider text-(--text-muted) sm:text-7xl md:text-8xl lg:text-9xl">404</p>
+			<h1 class="m-0 text-3xl sm:text-4xl md:text-5xl">Page not found</h1>
+			<p class="text-(--text-muted)">The page you requested does not exist, or it was moved.</p>
+			<p><a href="/" class="text-base text-(--accent) no-underline hover:underline">Back to catalog</a></p>
+		</section>
+	}
+}