scope text endpoints by ownership

TextRepository gains findByUser; JsonTextRepository and the
fake implement filtering by stored userId. TextController
splits the list endpoint into getMyTexts (own) and
getAllTexts (admin), and getText now requires the session
user, returning 403 to non-owners while admins bypass.

app/Text/JsonTextRepository.php

@@ -5,6 +5,7 @@ namespace App\Text;
 use App\Text\Text;
 use App\Text\CreateTextDto;
 use App\Text\TextRepository;
+use App\User\User;
 use App\User\UserRepository;
 use DomainException;
 
@@ -67,6 +68,28 @@ class JsonTextRepository implements TextRepository
         );
     }
 
+    /**
+     * @return Text[]
+     */
+    public function findByUser(User $user): array
+    {
+        $texts = $this->readTexts();
+        $userId = $user->getId();
+        $owned = array_filter(
+            $texts,
+            function (array $data) use ($userId) {
+                return $data['userId'] === $userId;
+            }
+        );
+
+        return array_map(
+            function (array $data) {
+                return $this->hydrate($data);
+            },
+            array_values($owned)
+        );
+    }
+
     private function hydrate(array $data): Text
     {
         $user = $this->userRepo->find($data['userId']);