complete new audit system

backend/src/controllers/contractHistory.controller.ts

@@ -1,5 +1,6 @@
 import { Request, Response } from 'express';
 import * as contractHistoryService from '../services/contractHistory.service.js';
+import { logChange } from '../services/audit.service.js';
 import { ApiResponse, AuthRequest } from '../types/index.js';
 
 export async function getHistoryEntries(req: AuthRequest, res: Response): Promise<void> {
@@ -35,6 +36,12 @@ export async function createHistoryEntry(req: AuthRequest, res: Response): Promi
       createdBy: req.user?.email || 'unbekannt',
     });
 
+    await logChange({
+      req, action: 'CREATE', resourceType: 'ContractHistory',
+      resourceId: entry.id.toString(),
+      label: `Historieneintrag "${title.trim()}" erstellt für Vertrag #${contractId}`,
+    });
+
     res.status(201).json({ success: true, data: entry } as ApiResponse);
   } catch (error) {
     res.status(400).json({
@@ -55,6 +62,12 @@ export async function updateHistoryEntry(req: AuthRequest, res: Response): Promi
       description: description?.trim(),
     });
 
+    await logChange({
+      req, action: 'UPDATE', resourceType: 'ContractHistory',
+      resourceId: entryId.toString(),
+      label: `Historieneintrag aktualisiert für Vertrag #${contractId}`,
+    });
+
     res.json({ success: true, data: entry } as ApiResponse);
   } catch (error) {
     res.status(400).json({
@@ -71,6 +84,12 @@ export async function deleteHistoryEntry(req: AuthRequest, res: Response): Promi
 
     await contractHistoryService.deleteHistoryEntry(contractId, entryId);
 
+    await logChange({
+      req, action: 'DELETE', resourceType: 'ContractHistory',
+      resourceId: entryId.toString(),
+      label: `Historieneintrag gelöscht für Vertrag #${contractId}`,
+    });
+
     res.json({ success: true, message: 'Eintrag gelöscht' } as ApiResponse);
   } catch (error) {
     res.status(400).json({