feat : add TaskDocument entity with Task relation

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

src/Entity/Task.php

@@ -99,9 +99,15 @@ class Task
     #[Groups(['task:read', 'task:write'])]
     private bool $archived = false;
 
+    /** @var Collection<int, TaskDocument> */
+    #[ORM\OneToMany(targetEntity: TaskDocument::class, mappedBy: 'task', cascade: ['remove'])]
+    #[Groups(['task:read'])]
+    private Collection $documents;
+
     public function __construct()
     {
-        $this->tags = new ArrayCollection();
+        $this->tags      = new ArrayCollection();
+        $this->documents = new ArrayCollection();
     }
 
     public function getId(): ?int
@@ -250,4 +256,10 @@ class Task
 
         return $this;
     }
+
+    /** @return Collection<int, TaskDocument> */
+    public function getDocuments(): Collection
+    {
+        return $this->documents;
+    }
 }