feat: unified_search + ai_proactive plugins with Ollama Cloud DeepSeek V4

- unified_search: Hybride Suche (PostgreSQL FTS + pgvector + RRF Fusion)
  - 5 Search Providers (Contact, Company, Mail, File, Event)
  - KI Query Understanding (Fuzzy, Facetten via LiteLLM)
  - DMS Text-Extraction (PDF, DOCX, XLSX, PPTX)
  - Embedding Pipeline (ollama/nomic-embed-text, 768 Dim)
  - Background Jobs für Indexierung
  - Plugin-basierte Provider Registry

- ai_proactive: Proaktiver KI-Agent
  - Context-Tracking (Frontend → Backend → Event Bus)
  - Proactive Engine mit LLM Suggestion-Generierung
  - SSE Real-time Push an Frontend
  - 6 AI Tools für Tool Registry
  - Rate-Limiting + User Settings
  - Deep Analysis Background Jobs

- Frontend Integration:
  - useAIContext Hook, SuggestionSidebar, SuggestionBadge
  - ProactiveAISettings Page, Search API Client
  - Globale Suche auf neue API umgestellt

- Tests: test_unified_search.py + test_ai_proactive.py (alle bestanden)
- Config: Ollama Cloud DeepSeek V4 als Default, konfigurierbar
- Dependencies: PyMuPDF, python-docx, python-pptx, pgvector
- Bugfixes: notification type_key length, migration IF NOT EXISTS

frontend/src/api/hooks.ts

@@ -388,45 +388,9 @@ export function useGlobalSearch(query: string, entityTypes?: string[]) {
     queryKey: ['globalSearch', query, entityTypes],
     queryFn: async (): Promise<SearchResult[]> => {
       if (!query.trim()) return [];
-      const results: SearchResult[] = [];
-      const types = entityTypes && entityTypes.length > 0 ? entityTypes : ['company', 'contact'];
-      const tasks: Promise<void>[] = [];
-      if (types.includes('company')) {
-        tasks.push(
-          apiGet<PaginatedResponse<Company>>(`/companies?page=1&page_size=10&search=${encodeURIComponent(query)}`)
-            .then((data) => {
-              for (const item of data.items) {
-                results.push({
-                  type: 'company',
-                  id: item.id,
-                  name: item.name,
-                  description: item.industry || item.email || '',
-                  url: `/companies/${item.id}`,
-                });
-              }
-            })
-            .catch(() => {})
-        );
-      }
-      if (types.includes('contact')) {
-        tasks.push(
-          apiGet<PaginatedResponse<Contact>>(`/contacts?page=1&page_size=10&search=${encodeURIComponent(query)}`)
-            .then((data) => {
-              for (const item of data.items) {
-                results.push({
-                  type: 'contact',
-                  id: item.id,
-                  name: `${item.first_name} ${item.last_name}`,
-                  description: item.email || item.phone || '',
-                  url: `/contacts/${item.id}`,
-                });
-              }
-            })
-            .catch(() => {})
-        );
-      }
-      await Promise.all(tasks);
-      return results;
+      const { search } = await import('@/api/search');
+      const response = await search(query, entityTypes, 20);
+      return response.results || [];
     },
     enabled: query.trim().length > 0,
     staleTime: 30 * 1000,