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/Entity/MachineProductLink.php

@@ -45,10 +45,6 @@ class MachineProductLink
     #[ORM\JoinColumn(name: 'productId', referencedColumnName: 'id', nullable: false, onDelete: 'CASCADE')]
     private Product $product;
 
-    #[ORM\ManyToOne(targetEntity: TypeMachineProductRequirement::class, inversedBy: 'machineProductLinks')]
-    #[ORM\JoinColumn(name: 'typeMachineProductRequirementId', referencedColumnName: 'id', nullable: true, onDelete: 'SET NULL')]
-    private ?TypeMachineProductRequirement $typeMachineProductRequirement = null;
-
     #[ORM\ManyToOne(targetEntity: MachineProductLink::class, inversedBy: 'childLinks')]
     #[ORM\JoinColumn(name: 'parentLinkId', referencedColumnName: 'id', nullable: true, onDelete: 'CASCADE')]
     private ?MachineProductLink $parentLink = null;
@@ -132,18 +128,6 @@ class MachineProductLink
         return $this;
     }
 
-    public function getTypeMachineProductRequirement(): ?TypeMachineProductRequirement
-    {
-        return $this->typeMachineProductRequirement;
-    }
-
-    public function setTypeMachineProductRequirement(?TypeMachineProductRequirement $requirement): static
-    {
-        $this->typeMachineProductRequirement = $requirement;
-
-        return $this;
-    }
-
     public function getParentLink(): ?MachineProductLink
     {
         return $this->parentLink;