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.

.env.example

@@ -0,0 +1,26 @@
+PUBLIC_CMS_URL=http://localhost:3000
+PUBLIC_SITE_URL=https://www.windwiderstand.de
+PUBLIC_SITE_NAME=Windwiderstand
+PUBLIC_UMAMI_SCRIPT_URL=
+PUBLIC_UMAMI_WEBSITE_ID=
+
+# analytics.pm86.de Site-ID (Script-URL ist hartcodiert auf analytics.pm86.de)
+PUBLIC_ANALYTICS_PM86_SITE_ID=
+
+# Formbricks Feedback-Widget
+PUBLIC_FORMBRICKS_APP_URL=
+PUBLIC_FORMBRICKS_ENVIRONMENT_ID=
+
+# Persistenter Disk-Cache für /cms-images (Default: .cache/images)
+# IMAGE_CACHE_DIR=.cache/images
+# Optional: In-Memory-Einträge vor Disk-Lesen (Default 200)
+# IMAGE_CACHE_MAX_MEMORY=200
+
+# Optional: Legacy-Proxy /api/transform (In-Memory + optional Datei)
+# TRANSFORM_CACHE_MAX_ENTRIES=100
+# TRANSFORM_CACHE_DIR=.cache/transform
+
+# Shared Secret für RustyCMS Webhook → POST /api/revalidate
+# Gleicher Wert muss in der Webhook-URL als ?token=... hängen.
+# Generieren: openssl rand -hex 32
+REVALIDATE_TOKEN=