wip: implement transportation, pickups and parking

docs/FIELD_STATE_SYSTEM.md

@@ -215,6 +215,32 @@ The system supports real-time field state updates:
 
 This improvement ensures that the conditional field state system works seamlessly with HTMX for all field types, providing users with immediate feedback on their selections.
 
+### Transportation Services HTMX Integration
+
+Transportation services benefit significantly from the enhanced HTMX integration:
+
+**Service-Specific Triggers**: Transportation, pickup, and parking fields use individual input-level triggers for immediate state updates:
+
+```php
+// Transportation field HTMX configuration
+'attr' => [
+    'hx-post' => $this->urlGenerator->generate('booking_create_step_2_refresh'),
+    'hx-target' => '#booking-summary',
+    'hx-trigger' => 'change',
+],
+```
+
+**Conditional Field Updates**: When users change transportation type:
+- Pickup fields automatically show/hide based on bus vs. car selection
+- Parking field visibility toggles for car transport
+- Pricing updates reflect transportation service costs
+- Booking summary updates in real-time
+
+**Mutual Exclusivity**: The system ensures logical field relationships:
+- Car transport → Parking field visible, pickup fields hidden
+- Bus transport → Pickup fields visible, parking field hidden
+- No transport selected → Both pickup and parking hidden
+
 ## Extending the System
 
 ### Custom Conditions