feat: enhance EPD header with dynamic client data fetching

- Update EPD header to fetch and display real client data from database
- Add loading state while fetching client information
- Improve client name and birth date formatting
- Rename ClientDetailPage component to ClientRedirect for clarity
- Fix import path for ReleaseSidebar in documentation layout

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

app/(marketing)/documentatie/layout.tsx

@@ -6,7 +6,7 @@
 
 import type { ReactNode } from 'react'
 import { getAllReleases, getCategoryMetadata } from '@/lib/mdx/documentatie'
-import ReleaseSidebar from './components/release-sidebar-wrapper'
+import { ReleaseSidebar } from './components/release-sidebar'
 
 interface ReleasesLayoutProps {
   children: ReactNode