chore: Add developer docs page and update portal layout

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

developer-portal/components/DevPortalLayout.tsx

@@ -3,7 +3,7 @@
 import React from 'react'
 import Link from 'next/link'
 import { usePathname } from 'next/navigation'
-import { Book, Code, FileText, HelpCircle, Zap, Terminal, Database, Shield, ChevronRight, Clock } from 'lucide-react'
+import { Book, Code, FileText, HelpCircle, Zap, Terminal, Database, Shield, ChevronRight, Clock, BookOpen } from 'lucide-react'
 
 interface NavItem {
   title: string
@@ -66,6 +66,14 @@ const navigation: NavItem[] = [
       { title: 'Phase 2: Dokumentation', href: '/guides/phase2' },
     ],
   },
+  {
+    title: 'Systemdokumentation',
+    href: '/development/docs',
+    icon: <BookOpen className="w-4 h-4" />,
+    items: [
+      { title: 'Compliance Service', href: '/development/docs' },
+    ],
+  },
   {
     title: 'Changelog',
     href: '/changelog',