feat: Add comprehensive audit logging system

- Add audit logging for contacts (link company, create company from contact)
- Add audit logging for notes (create, update, delete)
- Add audit logging for companies (update, user assign/remove, reminder CRUD)
- Add audit logging for projects (update, user assign/remove)
- Add audit logging for todos (update, uncomplete)
- Add audit logging for time entries (update, delete)
- Add audit logging for timesheets (upload, delete)
- Add audit logging for user deletion
- Add pagination and filters to audit logs API (userId, action, resource, dateFrom, dateTo)
- Add endpoints for distinct actions and resources

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/controllers/admin.controller.js

@@ -1,6 +1,6 @@
 import * as adminService from '../services/admin.service.js';
 import * as statusService from '../services/status.service.js';
-import { logUserCreation, logRoleChange } from '../services/audit.service.js';
+import { logUserCreation, logRoleChange, logUserDeleted } from '../services/audit.service.js';
 import { triggerEventNotifications } from '../cron/index.js';
 
 /**
@@ -131,10 +131,19 @@ export const changeUserRole = async (req, res, next) => {
  */
 export const deleteUser = async (req, res, next) => {
   const { userId } = req.params;
+  const adminId = req.userId;
+  const ipAddress = req.ip || req.connection.remoteAddress;
+  const userAgent = req.headers['user-agent'];
 
   try {
+    // Get user info before deletion for audit
+    const userToDelete = await adminService.getUserById(userId);
+
     const result = await adminService.deleteUser(userId);
 
+    // Log user deletion
+    await logUserDeleted(adminId, userId, userToDelete.username, ipAddress, userAgent);
+
     res.status(200).json({
       success: true,
       message: 'Používateľ bol zmazaný',