v1.3.2: SEO fixes + map bugfixes

SEO:
- Landing page converted to Server Component (SSR)
- Extracted NavAuthButtons + ContactForm as client islands
- Removed fake aggregateRating from JSON-LD
- Added FAQPage JSON-LD schema (7 questions)
- Extended sitemap: /datenschutz, /spenden, /demo

Map fixes:
- WebGL context lost recovery (black tiles after inactivity)
- Page visibility handler for tile reload on tab switch
- Arrow direction: geographic bearing instead of screen angle
- All markers rotationAlignment viewport->map (geographic orientation)
- DEL key now deletes selected lines/polygons/arrows (not just symbols)
- Default drawing color: black

src/app/sitemap.ts

@@ -23,10 +23,10 @@ export default function sitemap(): MetadataRoute.Sitemap {
       priority: 0.8,
     },
     {
-      url: `${baseUrl}/impressum`,
+      url: `${baseUrl}/demo`,
       lastModified: new Date(),
-      changeFrequency: 'yearly',
-      priority: 0.3,
+      changeFrequency: 'monthly',
+      priority: 0.7,
     },
     {
       url: `${baseUrl}/spenden`,
@@ -34,5 +34,17 @@ export default function sitemap(): MetadataRoute.Sitemap {
       changeFrequency: 'monthly',
       priority: 0.5,
     },
+    {
+      url: `${baseUrl}/datenschutz`,
+      lastModified: new Date(),
+      changeFrequency: 'yearly',
+      priority: 0.3,
+    },
+    {
+      url: `${baseUrl}/impressum`,
+      lastModified: new Date(),
+      changeFrequency: 'yearly',
+      priority: 0.3,
+    },
   ]
 }