Categorize components/ui into primitives, overlay, media, forms and layout

Splits the flat 38-component ui/ folder into primitives/ (generic
controls), overlay/ (menus/modals), media/ (music-domain display
components), forms/ (composite entity forms) and layout/ (page
scaffolding), and updates every import path accordingly.

web-player/src/lib/components/ui/overlay/ConfirmDialog.svelte

@@ -0,0 +1,26 @@
+<script lang="ts">
+	import Modal from './Modal.svelte';
+	import Button from '../primitives/Button.svelte';
+
+	interface Props {
+		open: boolean;
+		onClose: () => void;
+		title: string;
+		description: string;
+		confirmLabel: string;
+		action: string;
+	}
+
+	let { open, onClose, title, description, confirmLabel, action }: Props = $props();
+</script>
+
+<Modal {open} {onClose} maxWidth="max-w-sm">
+	<h2 class="text-display-3 text-fg">{title}</h2>
+	<p class="mt-2.5 text-body text-fg-2">{description}</p>
+	<div class="mt-6 flex items-center justify-end gap-3">
+		<Button variant="secondary" onclick={onClose}>Cancelar</Button>
+		<form method="POST" {action}>
+			<Button type="submit" variant="danger">{confirmLabel}</Button>
+		</form>
+	</div>
+</Modal>