feat: Refactor event equipment management with advanced selection and conflict detection

This commit introduces a complete overhaul of how equipment is assigned to events, focusing on an enhanced user experience, advanced selection capabilities, and robust conflict detection.

**Key Features & Enhancements:**

-   **Advanced Equipment Selection UI (`EquipmentSelectionDialog`):**
    -   New full-screen dialog to select equipment and containers ("boîtes") for an event.
    -   Hierarchical view showing containers and a flat list of all individual equipment.
    -   Real-time search and filtering by equipment category.
    -   Side panel summarizing the current selection and providing recommendations for containers based on selected equipment.
    -   Supports quantity selection for consumables and cables.

-   **Conflict Detection & Management (`EventAvailabilityService`):**
    -   A new service (`EventAvailabilityService`) checks for equipment availability against other events based on the selected date range.
    -   The selection dialog visually highlights equipment and containers with scheduling conflicts (e.g., already used, partially unavailable).
    -   A dedicated conflict resolution dialog (`EquipmentConflictDialog`) appears if conflicting items are selected, allowing the user to either remove them or force the assignment.

-   **Integrated Event Form (`EventAssignedEquipmentSection`):**
    -   The event creation/editing form now includes a new section for managing assigned equipment.
    -   It clearly displays assigned containers and standalone equipment, showing the composition of each container.
    -   Integrates the new selection dialog, ensuring all assignments are checked for conflicts before being saved.

-   **Event Preparation & Return Workflow (`EventPreparationPage`):**
    -   New page (`EventPreparationPage`) for managing the check-out (preparation) and check-in (return) of equipment for an event.
    -   Provides a checklist of all assigned equipment.
    -   Users can validate each item, with options to "validate all" or finalize with missing items.
    -   Includes a dialog (`MissingEquipmentDialog`) to handle discrepancies.
    -   Supports tracking returned quantities for consumables.

**Data Model and Other Changes:**

-   The `EventModel` now includes `assignedContainers` to explicitly link containers to an event.
-   `EquipmentAssociatedEventsSection` on the equipment detail page is now functional, displaying current, upcoming, and past events for that item.
-   Added deployment and versioning scripts (`scripts/deploy.js`, `scripts/increment_version.js`, `scripts/toggle_env.js`) to automate the release process.
-   Introduced an application version display in the main drawer (`AppVersion`).

em2rp/lib/controllers/event_form_controller.dart

@@ -34,6 +34,8 @@ class EventFormController extends ChangeNotifier {
   List<Map<String, dynamic>> _selectedOptions = [];
   bool _formChanged = false;
   EventStatus _selectedStatus = EventStatus.waitingForApproval;
+  List<EventEquipment> _assignedEquipment = [];
+  List<String> _assignedContainers = [];
 
   // Getters
   DateTime? get startDateTime => _startDateTime;
@@ -49,6 +51,8 @@ class EventFormController extends ChangeNotifier {
   bool get isLoadingUsers => _isLoadingUsers;
   List<Map<String, String>> get uploadedFiles => _uploadedFiles;
   List<Map<String, dynamic>> get selectedOptions => _selectedOptions;
+  List<EventEquipment> get assignedEquipment => _assignedEquipment;
+  List<String> get assignedContainers => _assignedContainers;
   bool get formChanged => _formChanged;
   EventStatus get selectedStatus => _selectedStatus;
 
@@ -95,6 +99,8 @@ class EventFormController extends ChangeNotifier {
     addressController.text = event.address;
     _startDateTime = event.startDateTime;
     _endDateTime = event.endDateTime;
+    _assignedEquipment = List<EventEquipment>.from(event.assignedEquipment);
+    _assignedContainers = List<String>.from(event.assignedContainers);
     _selectedEventTypeId = event.eventTypeId.isNotEmpty ? event.eventTypeId : null;
     _selectedUserIds = event.workforce.map((ref) => ref.id).toList();
     _uploadedFiles = List<Map<String, String>>.from(event.documents);
@@ -206,6 +212,13 @@ class EventFormController extends ChangeNotifier {
     notifyListeners();
   }
 
+  void setAssignedEquipment(List<EventEquipment> equipment, List<String> containers) {
+    _assignedEquipment = equipment;
+    _assignedContainers = containers;
+    _onAnyFieldChanged();
+    notifyListeners();
+  }
+
   Future<void> pickAndUploadFiles() async {
     final result = await FilePicker.platform.pickFiles(allowMultiple: true, withData: true);
     if (result != null && result.files.isNotEmpty) {
@@ -297,6 +310,10 @@ class EventFormController extends ChangeNotifier {
           documents: finalDocuments,
           options: _selectedOptions,
           status: _selectedStatus,
+          assignedEquipment: _assignedEquipment,
+          assignedContainers: _assignedContainers,
+          preparationStatus: existingEvent.preparationStatus,
+          returnStatus: existingEvent.returnStatus,
         );
 
         await EventFormService.updateEvent(updatedEvent);
@@ -335,6 +352,8 @@ class EventFormController extends ChangeNotifier {
           documents: _uploadedFiles,
           options: _selectedOptions,
           status: _selectedStatus,
+          assignedContainers: _assignedContainers,
+          assignedEquipment: _assignedEquipment,
         );
 
         final eventId = await EventFormService.createEvent(newEvent);