feat: ajout champs submitter + PDFs Vich sur Devis + protection uploads

src/Entity/Devis.php:
- submitterSiteconseilId (int nullable): ID du soumetteur cote SITECONSEIL
  dans DocuSeal apres signature
- submitterCustomerId (int nullable): ID du soumetteur cote client
  dans DocuSeal apres signature
- unsignedPdf (string nullable) + unsignedPdfFile (Vich): PDF non signe
- signedPdf (string nullable) + signedPdfFile (Vich): PDF signe
- auditPdf (string nullable) + auditPdfFile (Vich): certificat d'audit
- updatedAt (DateTimeImmutable nullable): mis a jour automatiquement
  a chaque upload de fichier via les setters *File()
- Annotation #[Vich\Uploadable] sur la classe
- Les 3 champs fichier utilisent le mapping 'devis_pdf'

config/packages/vich_uploader.yaml:
- Nouveau mapping devis_pdf: stockage dans public/uploads/devis
  avec SmartUniqueNamer pour eviter les collisions de noms

config/packages/security.yaml:
- Nouvelle regle access_control: /uploads/devis requiert ROLE_USER
  (empeche l'acces aux PDF de devis sans etre connecte)

migrations/Version20260402203334.php:
- Ajout colonnes submitter_siteconseil_id, submitter_customer_id,
  unsigned_pdf, signed_pdf, audit_pdf, updated_at sur la table devis

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

migrations/Version20260402203334.php

@@ -0,0 +1,41 @@
+<?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 Version20260402203334 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 submitter_siteconseil_id INT DEFAULT NULL');
+        $this->addSql('ALTER TABLE devis ADD submitter_customer_id INT DEFAULT NULL');
+        $this->addSql('ALTER TABLE devis ADD unsigned_pdf VARCHAR(255) DEFAULT NULL');
+        $this->addSql('ALTER TABLE devis ADD signed_pdf VARCHAR(255) DEFAULT NULL');
+        $this->addSql('ALTER TABLE devis ADD audit_pdf VARCHAR(255) DEFAULT NULL');
+        $this->addSql('ALTER TABLE devis ADD updated_at TIMESTAMP(0) WITHOUT TIME ZONE DEFAULT 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 submitter_siteconseil_id');
+        $this->addSql('ALTER TABLE devis DROP submitter_customer_id');
+        $this->addSql('ALTER TABLE devis DROP unsigned_pdf');
+        $this->addSql('ALTER TABLE devis DROP signed_pdf');
+        $this->addSql('ALTER TABLE devis DROP audit_pdf');
+        $this->addSql('ALTER TABLE devis DROP updated_at');
+    }
+}