feat(versioning) : add entity versioning with numbered versions and restore

Backend:
- Migration: version column on audit_logs and machines
- AuditLog, Machine, Composant, Piece, Product: version + skipAudit properties
- AbstractAuditSubscriber: auto-increment version, skip on restore, fix decimal diff
- Enriched snapshots with slots, custom fields and version number
- AuditLogRepository: findVersionHistory, findByVersion
- EntityVersionService: list, preview, restore with skeleton/integrity checks
- EntityVersionController: REST endpoints for all 4 entity types
- 11 tests covering list, preview, restore, auth

Frontend: update submodule pointer

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/Entity/Machine.php

@@ -108,6 +108,15 @@ class Machine
     #[ORM\Column(type: Types::DATETIME_IMMUTABLE, name: 'createdAt')]
     private DateTimeImmutable $createdAt;
 
+    #[ORM\Column(type: Types::INTEGER, options: ['default' => 1])]
+    private int $version = 1;
+
+    /**
+     * Transient flag — when true, audit subscribers skip this entity.
+     * Used by EntityVersionService::restore() to avoid duplicate AuditLogs.
+     */
+    private bool $skipAudit = false;
+
     #[ORM\Column(type: Types::DATETIME_IMMUTABLE, name: 'updatedAt')]
     private DateTimeImmutable $updatedAt;
 
@@ -265,4 +274,28 @@ class Machine
     {
         return $this->customFieldValues;
     }
+
+    public function getVersion(): int
+    {
+        return $this->version;
+    }
+
+    public function incrementVersion(): static
+    {
+        ++$this->version;
+
+        return $this;
+    }
+
+    public function getSkipAudit(): bool
+    {
+        return $this->skipAudit;
+    }
+
+    public function setSkipAudit(bool $skipAudit): static
+    {
+        $this->skipAudit = $skipAudit;
+
+        return $this;
+    }
 }