feat: Extract Developer Portal as standalone Next.js app on port 3006

SDK customers can now access the documentation publicly without login.
The portal runs independently from admin-v2 on https://macmini:3006/.

- New developer-portal/ app with 26 pages, 2 components
- Docker service + nginx SSL reverse proxy on port 3006
- All /developers/* routes remapped to /* in the new app
- admin-v2 developer pages remain unchanged

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -18,6 +18,7 @@ services:
       - "8089:8089"    # HTTPS Edu-Search proxy (edu-search runs on 8088)
       - "8093:8093"    # HTTPS AI Compliance SDK
       - "8443:8443"    # HTTPS Jitsi Meet (https://macmini:8443/)
+      - "3006:3006"    # HTTPS Developer Portal (https://macmini:3006/)
     volumes:
       - ./nginx/conf.d:/etc/nginx/conf.d:ro
       - vault_certs:/etc/nginx/certs:ro
@@ -40,6 +41,8 @@ services:
         condition: service_started
       jitsi-web:
         condition: service_started
+      developer-portal:
+        condition: service_started
     extra_hosts:
       - "breakpilot-edu-search:host-gateway"
     networks:
@@ -756,6 +759,24 @@ services:
       - breakpilot-pwa-network
     restart: unless-stopped
 
+  # ============================================
+  # Developer Portal - Oeffentliches SDK-Dokumentationsportal
+  # Access: https://macmini:3006/
+  # ============================================
+  developer-portal:
+    build:
+      context: ./developer-portal
+      dockerfile: Dockerfile
+    platform: linux/arm64
+    container_name: breakpilot-pwa-developer-portal
+    expose:
+      - "3000"
+    environment:
+      - NODE_ENV=production
+    networks:
+      - breakpilot-pwa-network
+    restart: unless-stopped
+
   # ============================================
   # AI Compliance SDK - Multi-Tenant RBAC & LLM Gateway
   # Go auf Port 8090 (intern), 8093 (extern)