refactor(api) : remove TypeMachine skeleton system, fix ModelType serialization

- Remove TypeMachine, TypeMachineComponentRequirement, TypeMachinePieceRequirement,
  TypeMachineProductRequirement entities and related repositories/state processor
- Replace MachineSkeletonController with MachineStructureController
- Link CustomField directly to Machine instead of TypeMachine
- Add migration to drop TypeMachine tables and migrate custom fields to machines
- Fix ModelType serialization: Annotation\Groups → Attribute\Groups (Symfony 8 compat)
  and add product:read, composant:read, piece:read groups for embedded category display
- Fix Profile: same Annotation → Attribute import
- Fix SearchFilter: partial → ipartial on Comment and Document
- Update frontend submodule (remove skeleton pages/components, simplify machine creation)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/Controller/MachineCustomFieldsController.php

@@ -33,12 +33,7 @@ class MachineCustomFieldsController extends AbstractController
             return $this->json(['success' => false, 'error' => 'Machine not found.'], 404);
         }
 
-        $typeMachine = $machine->getTypeMachine();
-        if (!$typeMachine) {
-            return $this->json(['success' => true, 'machineId' => $machine->getId(), 'customFieldValues' => []]);
-        }
-
-        foreach ($typeMachine->getCustomFields() as $customField) {
+        foreach ($machine->getCustomFields() as $customField) {
             if (!$customField instanceof CustomField) {
                 continue;
             }