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/store/uiStore.ts

@@ -14,12 +14,14 @@ export interface UIState {
   theme: Theme;
   locale: Locale;
   sidebarOpen: boolean;
+  suggestionSidebarOpen: boolean;
   aiSidebarCollapsed: boolean;
   toasts: Toast[];
   setTheme: (theme: Theme) => void;
   setLocale: (locale: Locale) => void;
   toggleSidebar: () => void;
   setSidebarOpen: (open: boolean) => void;
+  toggleSuggestionSidebar: () => void;
   toggleAISidebar: () => void;
   setAISidebarCollapsed: (collapsed: boolean) => void;
   addToast: (toast: Omit<Toast, 'id'>) => void;
@@ -33,6 +35,7 @@ export const useUIStore = create<UIState>((set) => ({
   theme: (localStorage.getItem('leocrm_theme') as Theme) || 'light',
   locale: (localStorage.getItem('leocrm_lang') as Locale) || 'de',
   sidebarOpen: true,
+  suggestionSidebarOpen: false,
   aiSidebarCollapsed: true,
   toasts: [],
   setTheme: (theme) => {
@@ -45,6 +48,7 @@ export const useUIStore = create<UIState>((set) => ({
   },
   toggleSidebar: () => set((s) => ({ sidebarOpen: !s.sidebarOpen })),
   setSidebarOpen: (open) => set({ sidebarOpen: open }),
+  toggleSuggestionSidebar: () => set((s) => ({ suggestionSidebarOpen: !s.suggestionSidebarOpen })),
   toggleAISidebar: () => set((s) => ({ aiSidebarCollapsed: !s.aiSidebarCollapsed })),
   setAISidebarCollapsed: (collapsed) => set({ aiSidebarCollapsed: collapsed }),
   addToast: (toast) => {