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/MachinePieceLink.php

@@ -49,10 +49,6 @@ class MachinePieceLink
     #[ORM\JoinColumn(name: 'parentLinkId', referencedColumnName: 'id', nullable: true, onDelete: 'CASCADE')]
     private ?MachineComponentLink $parentLink = null;
 
-    #[ORM\ManyToOne(targetEntity: TypeMachinePieceRequirement::class, inversedBy: 'machinePieceLinks')]
-    #[ORM\JoinColumn(name: 'typeMachinePieceRequirementId', referencedColumnName: 'id', nullable: true, onDelete: 'SET NULL')]
-    private ?TypeMachinePieceRequirement $typeMachinePieceRequirement = null;
-
     /**
      * @var Collection<int, MachineProductLink>
      */
@@ -145,18 +141,6 @@ class MachinePieceLink
         return $this;
     }
 
-    public function getTypeMachinePieceRequirement(): ?TypeMachinePieceRequirement
-    {
-        return $this->typeMachinePieceRequirement;
-    }
-
-    public function setTypeMachinePieceRequirement(?TypeMachinePieceRequirement $requirement): static
-    {
-        $this->typeMachinePieceRequirement = $requirement;
-
-        return $this;
-    }
-
     public function getNameOverride(): ?string
     {
         return $this->nameOverride;