Adds Kasse (Cash Register) module and related components

Introduces comprehensive cash management functionality with multiple view components for tracking daily transactions, filtering, and reconciliation

Implements:
- Cash calculation and difference tracking
- Dynamic tab switching
- Checkbox selection and row expansion
- Date filtering and approval mechanisms

PlanTempus.Application/Features/Menu/Services/MockMenuService.cs

@@ -79,8 +79,8 @@ public class MockMenuService : IMenuService
                     {
                         Id = "pos",
                         Label = "Kasse",
-                        Icon = "ph-device-mobile",
-                        Url = "/pos",
+                        Icon = "ph-cash-register",
+                        Url = "/kasse",
                         MinimumRole = UserRole.Staff,
                         SortOrder = 3
                     }