[#SIRH-17] Ajouter un système de log des actions utilisateurs (#9)

| Numéro du ticket | Titre du ticket |
|------------------|-----------------|
|                  |                 |

## Description de la PR

## Modification du .env

## Check list

- [ ] Pas de régression
- [ ] TU/TI/TF rédigée
- [ ] TU/TI/TF OK
- [ ] CHANGELOG modifié

Reviewed-on: #9
Co-authored-by: tristan <tristan@yuno.malio.fr>
Co-committed-by: tristan <tristan@yuno.malio.fr>

migrations/Version20260330120000.php

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+final class Version20260330120000 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Create audit_logs table for tracking user actions.';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $this->addSql('CREATE TABLE audit_logs (
+            id SERIAL PRIMARY KEY,
+            employee_id INTEGER DEFAULT NULL,
+            username VARCHAR(180) NOT NULL,
+            action VARCHAR(30) NOT NULL,
+            entity_type VARCHAR(50) NOT NULL,
+            entity_id INTEGER DEFAULT NULL,
+            description TEXT NOT NULL,
+            changes JSON DEFAULT NULL,
+            affected_date DATE DEFAULT NULL,
+            created_at TIMESTAMP(0) WITHOUT TIME ZONE NOT NULL,
+            CONSTRAINT fk_audit_employee FOREIGN KEY (employee_id) REFERENCES employees (id) ON DELETE SET NULL
+        )');
+
+        $this->addSql('CREATE INDEX idx_audit_employee_created ON audit_logs (employee_id, created_at)');
+        $this->addSql('CREATE INDEX idx_audit_entity ON audit_logs (entity_type, entity_id)');
+        $this->addSql('CREATE INDEX idx_audit_created ON audit_logs (created_at)');
+        $this->addSql('CREATE INDEX idx_audit_affected_date ON audit_logs (affected_date)');
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('DROP TABLE audit_logs');
+    }
+}