feat: shared links custom URL (#19999)

* feat: custom url for shared links

* feat: use a separate route and query param

---------

Co-authored-by: Jason Rasmussen <jason@rasm.me>

web/src/routes/(user)/s/[slug]/+error.svelte

@@ -0,0 +1,5 @@
+<script lang="ts">
+  import SharedLinkErrorPage from '$lib/components/pages/SharedLinkErrorPage.svelte';
+</script>
+
+<SharedLinkErrorPage />

web/src/routes/(user)/s/[slug]/[[photos=photos]]/[[assetId=id]]/+page.svelte

@@ -0,0 +1,12 @@
+<script lang="ts">
+  import SharedLinkPage from '$lib/components/pages/SharedLinkPage.svelte';
+  import type { PageData } from './$types';
+
+  type Props = {
+    data: PageData;
+  };
+
+  let { data }: Props = $props();
+</script>
+
+<SharedLinkPage {data} />

web/src/routes/(user)/s/[slug]/[[photos=photos]]/[[assetId=id]]/+page.ts

@@ -0,0 +1,4 @@
+import { loadSharedLink } from '$lib/utils/shared-links';
+import type { PageLoad } from './$types';
+
+export const load = (async ({ params, url }) => loadSharedLink({ params, url })) satisfies PageLoad;