feat: ajout totalHt, totalTva, totalTtc sur Devis

src/Entity/Devis.php:
- totalHt: decimal(10,2) default 0.00, montant hors taxes du devis
- totalTva: decimal(10,2) default 0.00, montant de la TVA
- totalTtc: decimal(10,2) default 0.00, montant toutes taxes comprises
- Getters/setters pour les 3 champs

migrations/Version20260402203631.php:
- Ajout colonnes total_ht, total_tva, total_ttc sur la table devis

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

migrations/Version20260402203631.php

@@ -0,0 +1,35 @@
+<?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 Version20260402203631 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 devis ADD total_ht NUMERIC(10, 2) DEFAULT \'0.00\' NOT NULL');
+        $this->addSql('ALTER TABLE devis ADD total_tva NUMERIC(10, 2) DEFAULT \'0.00\' NOT NULL');
+        $this->addSql('ALTER TABLE devis ADD total_ttc NUMERIC(10, 2) DEFAULT \'0.00\' NOT NULL');
+    }
+
+    public function down(Schema $schema): void
+    {
+        // this down() migration is auto-generated, please modify it to your needs
+        $this->addSql('ALTER TABLE devis DROP total_ht');
+        $this->addSql('ALTER TABLE devis DROP total_tva');
+        $this->addSql('ALTER TABLE devis DROP total_ttc');
+    }
+}