feat: ajout des commentaires à la semaine (#15)

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

## Description de la PR

## Modification du .env

## Check list

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

Reviewed-on: #15
Co-authored-by: tristan <tristan@yuno.malio.fr>
Co-committed-by: tristan <tristan@yuno.malio.fr>

migrations/Version20260417100000.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+final class Version20260417100000 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Create employee_week_comments table for per-week admin annotations on the hours weekly view';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $this->addSql('CREATE TABLE employee_week_comments (id SERIAL NOT NULL, employee_id INT NOT NULL, week_start_date DATE NOT NULL, content TEXT NOT NULL, created_at TIMESTAMP(0) WITHOUT TIME ZONE NOT NULL, updated_at TIMESTAMP(0) WITHOUT TIME ZONE NOT NULL, PRIMARY KEY(id))');
+        $this->addSql('CREATE UNIQUE INDEX uniq_employee_week_comment ON employee_week_comments (employee_id, week_start_date)');
+        $this->addSql('CREATE INDEX idx_ewc_week_start ON employee_week_comments (week_start_date)');
+        $this->addSql('ALTER TABLE employee_week_comments ADD CONSTRAINT fk_ewc_employee FOREIGN KEY (employee_id) REFERENCES employees(id) ON DELETE CASCADE');
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('DROP TABLE employee_week_comments');
+    }
+}