feat : WIP prix au kilo et prix total sur les bovins

- Champ pricePerKg persisté sur Bovine + migration
- Getter calculé finalPrice = receivedWeight * pricePerKg
- Colonnes Prix/kg et Prix total sur inventory et case
- Ajustements de largeurs pour rentrer dans le layout

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

migrations/Version20260424132554.php

@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * Auto-generated Migration: Please modify to your needs!
+ */
+final class Version20260424132554 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return '';
+    }
+
+    public function up(Schema $schema): void
+    {
+        // this up() migration is auto-generated, please modify it to your needs
+        $this->addSql('ALTER TABLE bovine ADD price_per_kg DOUBLE PRECISION DEFAULT NULL');
+    }
+
+    public function down(Schema $schema): void
+    {
+        // this down() migration is auto-generated, please modify it to your needs
+        $this->addSql('ALTER TABLE bovine DROP price_per_kg');
+    }
+}