feat(frontend): unified explore search across local and YouTube Music

Explore now has Todo/Mi musica/YouTube Music filters (searching both by default), YouTube results share the local grid card style, and cards show the artist instead of the upload date.

frontend/src/routes/(app)/explore/+page.server.ts

@@ -4,48 +4,59 @@ import { createApiClient } from '$lib/server/api';
 
 const PAGE_SIZE = 24;
 
+type Source = 'all' | 'local' | 'yt';
+
+function parseSource(value: string | null): Source {
+	return value === 'local' || value === 'yt' ? value : 'all';
+}
+
 export const load: PageServerLoad = async ({ url, locals, fetch }) => {
 	const query = url.searchParams.get('q')?.trim() ?? '';
-	const src = url.searchParams.get('src') === 'yt' ? 'yt' : ('local' as const);
+	const src = parseSource(url.searchParams.get('src'));
 	const page = Math.max(1, Number(url.searchParams.get('page')) || 1);
 
 	const api = createApiClient({ fetch, accessToken: locals.accessToken ?? undefined });
 
-	if (src === 'yt') {
-		const emptyResults = { items: [], continuationToken: '' };
+	const wantsLocal = src !== 'yt';
+	const wantsYouTube = src !== 'local';
 
-		const playlistsPromise = locals.user
+	const tracksPromise = wantsLocal
+		? api.GET('/tracks', {
+				params: { query: { name: query || undefined, pageNumber: page, pageSize: PAGE_SIZE } }
+			})
+		: Promise.resolve(null);
+
+	const searchPromise =
+		wantsYouTube && query && locals.accessToken
+			? api.GET('/youtube/search', { params: { query: { query } } })
+			: Promise.resolve(null);
+
+	const playlistsPromise =
+		wantsYouTube && locals.user
 			? api.GET('/playlists/users/{userId}', {
 					params: { path: { userId: locals.user.sub }, query: { pageNumber: 1, pageSize: 50 } }
 				})
 			: Promise.resolve(null);
 
-		const searchPromise =
-			query && locals.accessToken
-				? api.GET('/youtube/search', { params: { query: { query } } })
-				: Promise.resolve(null);
+	const [tracksRes, searchRes, playlistsRes] = await Promise.all([
+		tracksPromise,
+		searchPromise,
+		playlistsPromise
+	]);
 
-		const [playlistsRes, searchRes] = await Promise.all([playlistsPromise, searchPromise]);
-
-		return {
-			src: 'yt' as const,
-			query,
-			ytResults: searchRes?.data ?? emptyResults,
-			ytError: Boolean(searchRes?.error),
-			playlists: playlistsRes?.data?.items ?? [],
-			needsAuth: !locals.user
-		};
-	}
-
-	const { data, error: err } = await api.GET('/tracks', {
-		params: { query: { name: query || undefined, pageNumber: page, pageSize: PAGE_SIZE } }
-	});
-
-	if (err || !data) {
+	if (wantsLocal && (tracksRes?.error || !tracksRes?.data)) {
 		error(502, 'No se pudieron cargar las canciones.');
 	}
 
-	return { src: 'local' as const, query, tracks: data };
+	return {
+		src,
+		query,
+		tracks: tracksRes?.data ?? null,
+		ytResults: searchRes?.data ?? null,
+		ytError: Boolean(searchRes?.error),
+		playlists: playlistsRes?.data?.items ?? [],
+		needsAuth: wantsYouTube && !locals.user
+	};
 };
 
 export const actions: Actions = {