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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "lageplan",
-  "version": "1.3.1",
+  "version": "1.3.2",
   "description": "Feuerwehr Lageplan - Krokier-App für Einsatzdokumentation",
   "private": true,
   "scripts": {