feat: Enhance insurance billing system to support supplementary insurance

- Updated CoverageRule and related entities to include franchise_percent instead of franchise_rials.
- Modified Appointment entity to carry supplementary insurance ID alongside base insurance.
- Implemented SessionBillingService to ensure finalized invoices for insured patient sessions.
- Created InvoiceFinalized event to trigger claims creation upon invoice finalization.
- Added BackfillMissingClaimsCommand to generate claims for finalized invoices without existing claims.
- Developed tests to validate the new functionality for supplementary insurance handling in appointments and claims.

migrations/Version20260729155428.php

@@ -0,0 +1,29 @@
+<?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 Version20260729155428 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Let an appointment carry a supplementary insurance next to its basic one, so the confirm step can bill both in chain.';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE appointments ADD insurance_supplementary_id INT DEFAULT NULL');
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE appointments DROP insurance_supplementary_id');
+    }
+}