feat: add Maison Work source type, rename ExternalMarket to Direktinserat, hide own portfolio from demand search by default

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

src/components/compare/CompareColumnHeader.tsx

@@ -4,7 +4,8 @@ import type { UnifiedMatchResult } from '../../domain/unifiedResult'
 
 const TYPE_META: Record<string, { label: string; color: string }> = {
   VERIFIED_PORTFOLIO:  { label: 'Verified Portfolio', color: '#1e3a5f' },
-  EXTERNAL_MARKET:     { label: 'Marktinserat',       color: '#d97706' },
+  EXTERNAL_MARKET:     { label: 'Direktinserat',      color: '#d97706' },
+  MAISON_WORK:         { label: 'Maison Work',        color: '#0369a1' },
   FUTURE_AVAILABILITY: { label: 'Zukunftssignal',     color: '#7c3aed' },
 }