Initial SvelteKit frontend port of windwiderstand.de

Full parity with Astro site: content rows, post/tag routes, pagination,
event badges + OSM map, comments, Live-Search via /api/search-index,
CMS image proxy, RSS, sitemap.

Deploy: Dockerfile + docker-compose.prod.yml + Gitea Actions workflow
to build + push to git.pm86.de registry and ssh-deploy to Contabo.

src/lib/components/Accordion.svelte

@@ -0,0 +1,29 @@
+<script lang="ts">
+  import type { Snippet } from "svelte";
+  import Icon from "@iconify/svelte";
+  import "$lib/iconify-offline";
+
+  let {
+    label,
+    open = false,
+    id = undefined,
+    class: cls = "",
+    children,
+  }: {
+    label: string;
+    open?: boolean;
+    id?: string;
+    class?: string;
+    children: Snippet;
+  } = $props();
+</script>
+
+<details {id} {open} class="pt-4 border-t border-zinc-200 group {cls}">
+  <summary class="flex cursor-pointer list-none items-center gap-2 text-sm font-medium select-none">
+    <Icon icon="mdi:chevron-right" class="size-4 shrink-0 transition-transform group-open:rotate-90" />
+    {label}
+  </summary>
+  <div class="mt-4">
+    {@render children()}
+  </div>
+</details>