Add kilometer-based Fahrtkosten billing, self-service distance entry, role deletion

- Facility: TravelCostMode (Pauschale/ProKilometer) + TravelCostPerKm, alongside
  the existing flat rate; fixes FacilityService.UpdateAsync silently dropping all
  Konditionen fields on update.
- New EmployeeFacilityDistance (Mitarbeiter x Einrichtung -> km) with full
  office-side CRUD in omsorgapp, plus a self-service endpoint/UI so field staff
  can maintain their own commute distance via OMSORG Connect (new
  ModuleType.EmployeeFacilityDistances, Own-scope, no Facilities access needed).
- Roles can now be deleted (blocked with a 409 while still assigned to a user).
- Fix employeesApi.js missing the Date-object conversion for dateOfBirth/entryDate/
  exitDate that crashed employee creation whenever a date was filled in; add a
  clear/remove control for those date fields.
- Requirements: flesh out FR-REC-3 with a staged Akquise cadence, add FR-REC-5/6
  for CRM feature scope and success metrics.
- Regenerate api-client-ts and api-client-php for all of the above.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

omsorgWeb/mitarbeiter-app/api-client-php/docs/Model/FacilityResponse.md

@@ -24,6 +24,8 @@ Name | Type | Description | Notes
 **sunday_surcharge_percent** | **float** |  | [optional]
 **holiday_surcharge_percent** | **float** |  | [optional]
 **travel_cost_rate** | **float** |  | [optional]
+**travel_cost_mode** | **string** |  | [optional]
+**travel_cost_per_km** | **float** |  | [optional]
 **minimum_hours** | **float** |  | [optional]
 **break_policy** | **string** |  | [optional]
 **billing_interval** | **string** |  | [optional]