feat: AI Control Settings mit Category Control und Company Labels

MAJOR FEATURES:
- AI Control Tab in Settings hinzugefügt mit vollständiger KI-Steuerung
- Category Control: Benutzer können Kategorien aktivieren/deaktivieren und Aktionen pro Kategorie festlegen (Keep in Inbox, Archive & Mark Read, Star)
- Company Labels: Automatische Erkennung bekannter Firmen (Amazon, Google, Microsoft, etc.) und optionale benutzerdefinierte Company Labels
- Auto-Detect Companies Toggle: Automatische Label-Erstellung für bekannte Firmen

UI/UX VERBESSERUNGEN:
- Sorting Rules Tab entfernt (war zu verwirrend)
- Save Buttons nach oben rechts verschoben (Category Control und Company Labels)
- Company Labels Section: Custom Labels sind jetzt in einem ausklappbaren Details-Element (Optional)
- Verbesserte Beschreibungen und Klarheit in der UI

BACKEND ÄNDERUNGEN:
- Neue API Endpoints: /api/preferences/ai-control (GET/POST) und /api/preferences/company-labels (GET/POST/DELETE)
- AI Sorter Service erweitert: detectCompany(), matchesCompanyLabel(), getCategoryAction(), getEnabledCategories()
- Database Service: Default-Werte und Merge-Logik für erweiterte User Preferences
- Email Routes: Integration der neuen AI Control Einstellungen in Gmail und Outlook Sortierung
- Label-Erstellung: Nur für enabledCategories, Custom Company Labels mit orange Farbe (#ff9800)

FRONTEND ÄNDERUNGEN:
- Neue TypeScript Types: client/src/types/settings.ts (AIControlSettings, CompanyLabel, CategoryInfo, KnownCompany)
- Settings.tsx: Komplett überarbeitet mit AI Control Tab, Category Toggles, Company Labels Management
- API Client erweitert: getAIControlSettings(), saveAIControlSettings(), getCompanyLabels(), saveCompanyLabel(), deleteCompanyLabel()
- Debug-Logs hinzugefügt für Troubleshooting (main.tsx, App.tsx, Settings.tsx)

BUGFIXES:
- JSX Syntax-Fehler behoben: Fehlende schließende </div> Tags in Company Labels Section
- TypeScript Typ-Fehler behoben: saved.data null-check für Company Labels
- Struktur-Fehler behoben: Conditional Blocks korrekt verschachtelt

TECHNISCHE DETAILS:
- 9 Kategorien verfügbar: VIP, Clients, Invoices, Newsletter, Promotions, Social, Security, Calendar, Review
- Company Labels unterstützen Bedingungen wie 'from:amazon.com OR from:amazon.de'
- Priorisierung: 1) Custom Company Labels, 2) Auto-Detected Companies, 3) AI Categorization
- Deaktivierte Kategorien werden automatisch als 'review' kategorisiert

server/index.mjs

@@ -106,6 +106,105 @@ app.post('/api/preferences', asyncHandler(async (req, res) => {
   respond.success(res, null, 'Einstellungen gespeichert')
 }))
 
+/**
+ * GET /api/preferences/ai-control
+ * Get AI Control settings
+ */
+app.get('/api/preferences/ai-control', asyncHandler(async (req, res) => {
+  const { userId } = req.query
+  if (!userId) throw new ValidationError('userId is required')
+  
+  const prefs = await userPreferences.getByUser(userId)
+  const preferences = prefs?.preferences || userPreferences.getDefaults()
+  
+  respond.success(res, {
+    enabledCategories: preferences.enabledCategories || [],
+    categoryActions: preferences.categoryActions || {},
+    autoDetectCompanies: preferences.autoDetectCompanies !== undefined ? preferences.autoDetectCompanies : true,
+  })
+}))
+
+/**
+ * POST /api/preferences/ai-control
+ * Save AI Control settings
+ */
+app.post('/api/preferences/ai-control', asyncHandler(async (req, res) => {
+  const { userId, enabledCategories, categoryActions, autoDetectCompanies } = req.body
+  if (!userId) throw new ValidationError('userId is required')
+  
+  const updates = {}
+  if (enabledCategories !== undefined) updates.enabledCategories = enabledCategories
+  if (categoryActions !== undefined) updates.categoryActions = categoryActions
+  if (autoDetectCompanies !== undefined) updates.autoDetectCompanies = autoDetectCompanies
+  
+  await userPreferences.upsert(userId, updates)
+  respond.success(res, null, 'AI Control settings saved')
+}))
+
+/**
+ * GET /api/preferences/company-labels
+ * Get company labels
+ */
+app.get('/api/preferences/company-labels', asyncHandler(async (req, res) => {
+  const { userId } = req.query
+  if (!userId) throw new ValidationError('userId is required')
+  
+  const prefs = await userPreferences.getByUser(userId)
+  const preferences = prefs?.preferences || userPreferences.getDefaults()
+  
+  respond.success(res, preferences.companyLabels || [])
+}))
+
+/**
+ * POST /api/preferences/company-labels
+ * Save/Update company label
+ */
+app.post('/api/preferences/company-labels', asyncHandler(async (req, res) => {
+  const { userId, companyLabel } = req.body
+  if (!userId) throw new ValidationError('userId is required')
+  if (!companyLabel) throw new ValidationError('companyLabel is required')
+  
+  const prefs = await userPreferences.getByUser(userId)
+  const preferences = prefs?.preferences || userPreferences.getDefaults()
+  
+  const companyLabels = preferences.companyLabels || []
+  
+  // Generate ID if not provided
+  if (!companyLabel.id) {
+    companyLabel.id = `label_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`
+  }
+  
+  // Update or add label
+  const existingIndex = companyLabels.findIndex(l => l.id === companyLabel.id)
+  if (existingIndex >= 0) {
+    companyLabels[existingIndex] = companyLabel
+  } else {
+    companyLabels.push(companyLabel)
+  }
+  
+  await userPreferences.upsert(userId, { companyLabels })
+  respond.success(res, companyLabel, 'Company label saved')
+}))
+
+/**
+ * DELETE /api/preferences/company-labels/:id
+ * Delete company label
+ */
+app.delete('/api/preferences/company-labels/:id', asyncHandler(async (req, res) => {
+  const { userId } = req.query
+  const { id } = req.params
+  if (!userId) throw new ValidationError('userId is required')
+  if (!id) throw new ValidationError('label id is required')
+  
+  const prefs = await userPreferences.getByUser(userId)
+  const preferences = prefs?.preferences || userPreferences.getDefaults()
+  
+  const companyLabels = (preferences.companyLabels || []).filter(l => l.id !== id)
+  
+  await userPreferences.upsert(userId, { companyLabels })
+  respond.success(res, null, 'Company label deleted')
+}))
+
 // Legacy Stripe webhook endpoint
 app.use('/stripe', stripeRoutes)